Surgical instrument

ABSTRACT

A program of instructions for the processor which include: receiving an insertion length of a medical instrument inserted in a patient; and determining a distal end location of the instrument at a target site in the patient from the insertion length. The instrument typically has a straight proximal portion and curved distal portion, lies in a single plane and is a rigid guide member. The instrument is typically inserted and then fixed at a pivot axis outside the patient. The pivot axis is generally aligned with an insertion point at which the instrument is inserted into the patient. The program of instructions may include determining a subsequent location of the distal end associated with pivoting about the pivot axis. The program of instructions may include determining a subsequent location of the distal end associated with axial rotation of the instrument, determining a subsequent location of the distal end associated with linear translation along a length axis of the instrument and/or determining a subsequent movement of the distal end in a single plane about the pivot axis. The pivotal axis is typically a reference point used by the program of instructions in determining subsequent movement of the distal end.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to surgical instruments and moreparticularly to surgical instruments which are remotely controlled byelectronic control signals generated by a user which are sent to a driveunit which drives mechanically drivable components of a mechanicalapparatus which support a surgical instrument.

SUMMARY OF THE INVENTION Instrument Support and Mounting

[0002] One aspect of the present invention relates to a support memberfor holding a medical procedure instrument holder in a fixed positionrelative to a patient.

[0003] In one embodiment, a medical procedure instrument is provided,including an instrument holder, an instrument insert, and a support. Theinstrument holder includes an elongated guide member for receiving theinstrument insert. The insert carries on its distal end a medical toolfor executing the medical procedure. The instrument holder is manuallyinsertable into a patient so as to dispose a distal end of the guidemember into a target site in which the procedure is to be executed. Thesupport holds the instrument holder fixed in position relative to thepatient. The instrument holder is held in fixed position in an incisionin the patient between changes of instrument inserts during the courseof a procedure such that trauma or damage which can result fromwithdrawal and re-insertion of another or the same instrument isminimized or eliminated. The distal end of the elongated guide member ispreferably curved and at least the distal end of the instrument insertis flexible to enable the insert to slide through the curved distal endof the guide member.

[0004] The instrument insert typically includes an elongated shafthaving a proximal end, a distal end and a selected length between thetwo ends. One or more portions of the elongated shaft along its length,and most typically a distal end portion, may comprise a mechanically andcontrollably deformable material such that the portion of the selectedlengths of the shaft which are deformable are controllably bendable orflexible in any one or more of an X, Y and Z axis direction relative tothe axis of the shaft thus providing an additional three degrees offreedom of movement control. Flexible cables, rods or the like which areconnected at one end to a deformable or flexible portion of a shaft andare drivably intercoupled to a controllably drivable drive unit aretypically included for effecting control of the bending or flexing.

[0005] In one embodiment, the support includes a bracket that holds aninstrument holder to the support at a fixed reference point. Theinstrument holder is then pivotally supported at this reference pointfrom the bracket.

[0006] In various embodiments, the instrument insert is manuallyengageable and disengageable with the instrument holder. Generally, theinstrument holder is inserted into the patient first, and then theinsert is engaged to the holder, such that the medical tool at thedistal end of the insert extends beyond the distal end of the guidemember at the target site. One advantage is to maintain the guide memberwith its distal end at the target site upon withdrawal of the instrumentinsert. This enables exchange of instrument inserts during the procedureand facilitates ease of placement of the next instrument insert.

[0007] The instrument insert preferably includes a mechanically drivablemechanism for operating the medical tool. The instrument holder alsoincludes a mechanical drive mechanism such that the drive and drivablemechanisms are engageable and disengageable with one another, in orderto enable engagement and disengagement between the insert and holder.Preferably, a drive unit for controlling the instrument insert andholder is disposed remote from the insert and holder, outside of asterile field which may be defined by the area above the operatingtable.

[0008] In another embodiment, a medical procedure instrument is providedwhich includes an instrument holder, an instrument insert, and asupport. The instrument holder includes an elongated guide member forreceiving the insert, the insert carrying at its distal end a medicaltool for executing a medical procedure. The support holds the instrumentholder with a distal end of the guide member at a target site internalof the patient. The insert is adapted for ready insertion and withdrawalby way of the guide member, while the guide member is held at the targetsite. Again, this facilitates ready exchange of instrument insertsduring a medical procedure. The instrument inserts are preferablydisposable, so they can be discarded after a single insertion andwithdrawal from the patient.

[0009] In a further embodiment, a remote controlled instrument system isprovided which includes a user interface, an instrument, a support, anda controller. The user interface allows an operator to manually controlan input device. The instrument has at its distal end a tool forcarrying out a procedure, the instrument being manually inserted into apatient so as to dispose the tool at a target site at which theprocedure is to be executed. The support holds a part of the instrumentfixed in position relative to the patient. A controller coupled betweenthe user interface and the instrument is responsive to a remote controlby the operator for controlling the instrument at the target site.

[0010] Another embodiment is a method for remotely controlling aninstrument having multiple degrees-of-freedom. The instrument ismanually inserted into a patient so as to dispose its distal end at atarget site at which a procedure is to be executed. An instrumentholder, that receives the instrument, is supported stationary relativeto the patient during the procedure so as to maintain the instrumentdistal end at the target site. A user input device is used to remotelycontrol the motion of the instrument distal end in executing theprocedure at the target site.

[0011] In a further method embodiment for remotely controlling aninstrument, an instrument holder is provided for removably receiving andsupporting a disposable instrument insert. The instrument holder isinserted into a patient so as to dispose its distal end at an operativesite at which the procedure is to be executed. The instrument insert isreceived in the holder so as to dispose a tool at the distal end of theinsert so that it extends from the holder and is positioned at theoperative site. A user input device remotely controls motion of theinsert in executing the procedure at the operative site. Preferably, theinstrument holder is maintained at the operative site as the insert iswithdrawn, enabling ready exchange of one instrument insert for another.

[0012] The invention also provides a medical apparatus for exchangingsurgical instruments having a selected tool to be positioned at anoperative site of a subject, the apparatus comprising: a guide tubehaving an open distal end inserted through an incision of the subject,the guide tube being fixedly positioned relative to the subject suchthat the distal end of the guide tube is fixedly positioned at theoperative site, the guide tube being readily manually insertable throughthe incision; one or more surgical instruments each having a selectedtool mounted at a distal end of the instrument; wherein the one or moresurgical instruments are readily insertable through the fixedlypositioned guide tube such that the selected tool of an instrument isdisposed through the open distal end of the guide tube at the operativesite upon full insertion of the surgical instrument, the guide tubehaving a first mounting interface and the surgical instruments having asecond mounting interface, the first and second mounting interfacesbeing readily engageable with each other to fixedly mount the surgicalinstruments within the guide tube upon full insertion of the surgicalinstrument. Such a medical apparatus may further comprise a readilymanually portable support for fixedly positioning the guide tube in aselected location and orientation relative to the subject, the manuallyportable support being readily fixedly attachable to and detachable froma stationary structure on or relative to which the subject is mounted.

[0013] These and other embodiments of the instrument, system and methodare more particularly described in the later detailed descriptionsection.

Ready Attachability, Couplability and Mountability

[0014] Another aspect of the invention is to provide a drive unit ormotor assembly which is attachable and detachable from a medicalinstrument assembly in order to provide one or more of the features of,positioning the motor assembly outside a sterile field in which amedical procedure takes place, increasing portability of the instrumentassembly for ease of positioning with respect to the patient and ease ofaccess to the patient during the procedure, e.g., avoiding bulky andunnecessary electromechanical equipment in the sterile field of theprocedure so as to increase ease of access to the patient, enablingdetachment, sterilization and reusability of certain components of theinstrument assembly and/or detachment and disposability of certain otherportions of the instrument assembly.

[0015] In the first embodiment, a medical procedure instrument isprovided, including a medical implement and a drive unit. The medicalimplement includes a mechanically drivable mechanism intercoupled withthe tool used in executing a medical procedure. A drive unit, disposedremote from the medical implement, is used for mechanically driving theimplement. The implement is initially decoupled from the drive unit andmanually insertable into a patient so as to dispose the tool at anoperative site within the patient. The medical implement is attachableand detachable with the drive unit for coupling and decoupling themechanically drivable mechanism with the drive unit.

[0016] In various preferred embodiments, the medical implement includesa holder and an instrument insert, the holder receiving the insert andthe insert carries the mechanically drivable mechanism. Preferably, theinsert is an integral disposable unit, including a stem section with thetool at its distal end and the mechanically drivable mechanism at itsproximal end.

[0017] The drive unit may be an electromechanical unit, and mechanicalcabling may intercouple the drive unit with the mechanically drivablemechanism. Mechanical cabling may be provided to control motion for boththe instrument holder, and the instrument insert. The medical implementmay be remotely controllable by a user, manipulating a manuallycontrollable device, which device is connected to the drive unit throughan electrical drive control element.

[0018] In another embodiment, a slave station of a robotic surgerysystem is provided in which manipulations by a surgeon control motion ofa surgical instrument at a slave station. The slave station includes asupport, mechanical cabling, and a plurality of motors. The support ismanually portable and is provided to hold the surgical instrument at aposition over an operating table so that the instrument may be readilydisposed at an operative site. Mechanical cabling is coupled to theinstrument for controlling movement of the instrument. The plurality ofmotors are controlled, by way of a computer interface, and by surgeonmanipulations for driving the mechanical cabling. The mechanical cablingis driven by the plurality of motors in a manner so as to be attachableand detachable from the plurality of motors.

[0019] In a preferred embodiment, a two section housing is provided, onehousing section accommodating the ends of the mechanical cabling and theother housing section accommodating the plurality of motors. The twohousing sections are respectively attachable and detachable. A pluralityof coupler spindles supported by the one housing section receive cablesof the mechanical cabling. The plurality of coupler spindles andplurality motors are disposed in aligned arrays. A plurality of couplerdisks of the other housing section are provided, one associated with andsupported by each motor by the plurality of motors. The housing sectionssupport the coupler spindles and the coupler disks in alignedengagement. An engagement element may lock the coupler spindles anddisks against relative rotation.

[0020] In a further embodiment, a robotic surgery system is provided,including an instrument, a support, mechanical cabling, an array ofactuators, and an engagement member. The support is manually portableand holds the instrument over an operating table so that the instrumentmay be disposed at an operative site in a patient for remote controlthereof via a computer interface. The mechanical cabling is coupled tothe instrument for controlling movement of the instrument. An array ofelectrically driven actuators is controlled by the computer interfacefor driving the mechanical cabling. An engagement member intercouplesbetween the mechanical cabling and the array of actuators so that themechanical cabling is readily attachable to and detachable from thearray of actuators.

[0021] In another aspect of the invention, there is provided a roboticsurgery apparatus comprising: a mechanically drivable surgicalinstrument for use at an internal operative site of a subject; anelectrically driven drive unit for driving the surgical instrument;mechanical cabling drivably intercoupled to the surgical instrument atone end of the cabling; the mechanical cabling having another end whichis readily drivably couplable to and decouplable from the drive unit.

[0022] In another aspect of the invention, there is provided a roboticsurgery apparatus comprising: a surgical instrument for use at aninternal operative site of a subject; a mechanically drivable mountingunit on which the surgical instrument is mounted, the mounting unitbeing drivably movable outside the operative site of the subject; anelectrically driven drive unit for driving movement of the mountingunit; mechanical cabling drivably intercoupled to the mounting unit atone end of the cabling; the mechanical cabling having another end whichis readily drivably couplable to and decouplable from the drive unit.

[0023] In another aspect of the invention there is provided a roboticsurgery apparatus comprising: a mechanically drivable surgicalinstrument for use at an internal operative site of a subject; anelectrically driven drive unit for driving the surgical instrument;mechanical cabling drivably intercoupled to the surgical instrument atone end of the cabling; the drive unit being readily manually portableand readily attachable to and detachable from a fixed support on orrelative to which the subject is mounted.

[0024] These and other embodiments are described in the followingdetailed description section.

Disposability

[0025] Another aspect of the invention is to provide a disposablemedical procedure instrument which includes a mechanically drivablemechanism for driving a tool.

[0026] Disposable or disposability generally means that a device ormechanism is used or intended for a single use without a re-use of thedevice/mechanism and/or without the necessity or intention of a use ofthe device followed by sterilization of the device for an intendedre-use. In practice, a device which is intended for one time or singleuse may be re-used by the user/physician but such re-use more than once,twice or a very limited number of times is not intended for a disposabledevice or mechanism.

[0027] In one embodiment, a medical procedure instrument is providedincluding a disposable implement and a mounting mechanism interconnectedto a drive mechanism. The disposable implement includes a shaft having atool at its distal end and a mechanically drivable mechanism drivablyinterconnected to the tool. A mounting mechanism, interconnected to thedrive mechanism, enables the mechanically drivable mechanism of theimplement to be removably mounted on the mounting mechanism for drivableinterconnection to the drive mechanism. The shaft is insertable into apatient along a select length of the shaft to position the tool at atarget site in the patient. The shaft together with the mechanicallydrivable mechanism is disposable.

[0028] At various embodiments, the drive mechanism is drivablyinterconnected to the mounting mechanism at a first interface which isremote from a second interface at which the mechanically drivablemechanism is mounted to the mounting mechanism. The drive mechanism mayinclude a plurality of motors, and the mounting mechanism is preferablyattachable and detachable from the drive mechanism. The mountingmechanism may include a guide tube, through which the shaft is insertedinto the patient, and wherein the mounting mechanism includes a drivablemechanism for mechanically driving the guide tube.

[0029] Preferably, the disposable instrument can be removed from themounting mechanism and discarded after use, while the mounting mechanismcan be removed from the drive mechanism and sterilized for reuse.

[0030] The disposable implement is preferably remote controllablydrivable by a user via a manually controllable mechanism which iselectrically connected to the drive mechanism through an electricaldrive control mechanism.

[0031] Preferably, the mounting mechanism and the disposable implementare manually portable in a sterile field, while the drive mechanism isoutside the sterile field.

[0032] In another embodiment, a medical procedure instrument is providedwhich is a disposable instrument, drivably interconnectable to anddisconnectable from a drive mechanism, the disposable instrumentincluding a mechanically drivable interface, drivably interconnectedthrough a shaft to a tool, the mechanically drivably interface beingdrivably engageable with and disengageable from a second drive interfacewhich is drivably interconnected to the drive mechanism. Preferably, themechanically drivable interface and the shaft are an integral disposableunit. The disposable implement may be remote controllably drivable by auser via a manually controllable mechanism which is electricallyinterconnected to the drive mechanism through an electrical drivecontrol mechanism. The second drive interface may be manually portablein a sterile field. After use, the second drive interface is sterilizedfor reuse. The drive mechanism is outside the sterile field.

[0033] In yet another embodiment, a surgical instrument system isprovided positionable within an anatomic body structure and controllableby an operator. The system contains a guide member, a support, and anintegral instrument member. The guide member has a proximal end and adistal end. The support positions the guide member with the proximal endoutside the anatomic body structure and the distal end within theanatomic body structure adjacent to the operative site. An integralinstrument member, disposable as a unit, includes a mechanical drivableelement, a stem section and a distal tool. The instrument member isremovably engageable with the guide member.

[0034] In various embodiments, each of the instrument member and guidemember has a coupler, the couplers being removably engageable in orderto drive the mechanical drivable element of the instrument member. Atleast one motor is provided remote from the guide member and instrumentmember, and mechanical cabling is provided from the motor to theinstrument member coupler via the guide member coupler to provide atleast 1 degree-of-freedom of motion of the instrument member. Thecouplers may include interengageable wheels. The guide member coupler ispivotal to facilitate the removable engagement of the guide member andinstrument member.

[0035] In one embodiment, the guide member includes a base piece, and aguide tube extending from the base piece, wherein the coupler ispivotally supported from the base piece. The instrument member stemsection has a mechanical cabling extending therethrough from theinstrument member coupler to the distal tool. The instrument member stemsection may include sections with different amounts of flexibility. Theguide tube includes a straight section, and a more distal curvedsection. When the instrument member engages with the guide member, themore flexible stem section is disposed in the guide tube curved section.An electromechanical drive member may be provided remote from the guidetube and instrument member, having only mechanical coupling to the guidetube and instrument member. The mechanical coupling may control rotationof the guide tube as well as rotation of the instrument stem within theguide tube.

[0036] In another embodiment, a disposable integral medical instrumentis provided including a mechanical coupler, an elongated stem, and atool. The mechanical coupler is at the proximal end of instrument forreceiving mechanical drive from a drive unit. The elongated stem extendsfrom the mechanical coupler. The tool is disposed at the distal end ofthe elongated stem and is interconnected, via the elongated stem, to themechanical coupler. The elongated stem enables removable insertion in aninstrument holder to position a tool at a target site inside a patientfor performing a medical procedure.

[0037] Preferably, the disposable integral medical instrument isattachable to and detachable from an instrument holder in order tocouple mechanical drive from a remote drive unit. The mechanical couplerincludes at least one interlocking wheel for coupling with theinstrument holder. The mechanical coupler includes mechanical cablingextending to the tool. The stem is mounted to enable rotation of thestem relative to the mechanical coupler. A wrist joint may be providedat the distal end of the stem, coupling to the tool. The elongated stemmay have a more distal flexible section. The instrument may have a meansfor registering the mechanical coupler with an instrument holder.

[0038] In another aspect of the invention, there is provided adisposable surgical instrument comprising: a disposable elongated tubehaving a tool mounted at a distal end of the tube; one or moredisposable cables drivably interconnected between the tool and a driveunit, the one or more disposable cables extending through the disposabletube between the tool and a proximal end of the disposable tube. Theapparatus preferably includes a guide tube having an open distal end,the guide tube being readily manually insertable through an incision ina subject to position the distal end at an operative site within thesubject, the disposable elongated tube being readily insertable throughthe guide tube to position the tool through the open distal end of theguide tube. The apparatus preferably also includes a manually portablesupport readily fixedly attachable to and detachable from a stationarystructure on or relative to which the subject is mounted, the guide tubebeing readily fixedly interconnectable to and disconnectable from thesupport for fixedly positioning the distal end of the guide tube at theoperative site. The drive unit is preferably mounted remotely from theoperative site and is drivably interconnected to the one or more cablesextending through the disposable tube by one or more cables extendingbetween the drive unit and the proximal end of the disposable elongatedtube.

[0039] In another embodiment of the invention there is provided adisposable surgical instrument comprising: a disposable elongated tubehaving a tool mounted at a distal end of the tube; a disposablemechanically drivable interface mounted at a proximal end of thedisposable tube, the tool being drivably intercoupled to a drive unitvia the disposable mechanically drivable interface.

[0040] These and other features of the invention are set forth morefully in the following detailed description.

Translation and Other Movement Capability

[0041] Another aspect of the invention relates to controlled movement ofa surgical instrument system having a distal end positionable within apatient. More specifically, the controlled movement may be limited totranslation in a predetermined plane. This controlled movement specifiescertain degrees-of-freedom of the surgical instrument, including a guidetube that receives an instrument member having a tool at its distal end.Such movement may be remotely controlled via computer control inresponse to movements by a surgeon at an input interface.

[0042] In one embodiment, a surgical instrument system is provided thatis adapted to be inserted through an incision of a patient for operationby a surgeon from outside the patient. The system includes an armmember, a support for the arm member and an instrument member. The armmember has a proximal end disposed outside the patient and a distal endinternal of the patient. A support for the arm member providescontrolled translation of the arm member with a proximal end thereofmoving substantially only in a predetermined plane. The instrumentmember is carried by the arm member and includes a tool disposed at thedistal end of the arm member.

[0043] In a preferred embodiment, a controller responsive to a surgeonmanipulation controls movement of the arm member and of the tool. Thesurgeon may be positioned at a master station having an input interface,at which the surgeon manipulates an input device. The controller mayallow a number of degrees-of-freedom of the tool and of the arm member.In one embodiment, the tool has 4 degrees-of-freedom, while the armmember has 3 degrees-of-freedom. More specifically, the arm member mayhave one degree-of-freedom in the predetermined plane. The arm membermay have another degree-of-freedom that is rotation of the arm memberabout a longitudinal axis of the arm member. The arm member may have afurther degree-of-freedom that is linear movement of the arm memberalong the longitudinal axis of the arm member. The tool may have onedegree-of-freedom that is rotation of the instrument member about alongitudinal axis of the instrument member. The tool may have anotherdegree-of-freedom that is pivotal in a second plane orthogonal to thefirst plane. The tool may have jaws and a further degree-of-freedom maybe provided enabling opening and closing of the jaws.

[0044] The support for the arm member may include a support post forpositioning the arm member over an operating table upon which a patientis placed. Preferably, the support post positions the arm member at anacute angle to the operating table. The arm member may include a guidetube that receives the instrument member.

[0045] In another embodiment, a surgical instrument system is providedadapted to be inserted through an incision in a patient for operation bya surgeon from outside the patient. The system may include an instrumentmember having a tool at its distal end. The guide member has a guidetube with a proximal end disposed outside the patient and a distal endinternal of the patient. The guide tube has an elongated portion with acentral access of rotation and a distal portion having an end which ispositioned a radial distance away from the central access. The supportfor the guide member provides controlled translation of the guide memberwith the proximal end thereof moving substantially only in apredetermined plane.

[0046] In various embodiments, a drive unit is coupled to the guide tubefor rotating the guide tube and thereby displacing the tool with respectto the central access. Preferably, the distal portion of the guide tubeis curved so as to displace the end thereof the radial distance awayfrom the central access. When combined with translation in the plane,the rotation of the guide tube enables three-dimensional placement ofthe instrument tool.

[0047] The instrument member may include a coupler for engaging theinstrument member to the guide member, and an elongated section that is,at least, partially flexible for insertion into the guide tube. Theinstrument member may include in its distal end at least two adjacentlink members intercoupled by way of at least one joint, and at least onecable extending along at least one of the link members for operating theadjacent link member. Separate cable sections may be coupled to oppositesides of the adjacent link members for enabling pivoting in eitherdirection of the adjacent link member relative to the at least one linkmember.

[0048] The instrument member can be readily engageable and disengageablewith the guide member and constructed to enable exchange with otherinstrument members. The instrument member may be disposable.

[0049] The instrument member may be couplable to and decouplable from adrive unit, the drive unit being controlled by a controller foroperating the instrument member. The drive unit may be disposed remotefrom a sterile field in which the patient and instrument member aredisposed.

[0050] In another embodiment, an instrument system is provided,including a user interface, an instrument, a support, a controller, anda drive unit. A surgeon may manipulate an input device at the userinterface. The instrument has a distal end internal of the patient andcarrying at its distal end a tool used in executing a procedure at anoperative site of the patient. The support for the instrument includes apivot at the proximal end of the instrument that limits motion of theproximal end of the instrument substantially only in one plane. Thecontroller receives commands from the user interface for controllingmovement of the instrument. A drive unit intercouples with thecontroller and the instrument.

[0051] In a preferred embodiment, the instrument includes an adapter andan instrument insert. The adapter may have a guide tube with anelongated portion having a longitudinal access of rotation and a distalend that is positioned a radial distance away from the longitudinalaccess. When the distal end of the guide tube is curved, the distal endwill orbit about the longitudinal access as the guide tube is rotatedunder control from the user interface. The insert may be removablycouplable with the adapter and include an elongated stem having a toolat its distal end. The adapter and insert may each include a coupler forlateral relative coupling and decoupling of the adapter and insert. Theinstrument coupler may include a series of wheels that engage with aseries of wheels on the adapter coupler.

[0052] The instrument insert may have an elongated stem which includes amore flexible stem section disposed distally of a less flexible stemsection. Alternatively, the full length of the elongated stem may beflexible. A wrist link, intercoupling a more flexible stem section withthe tool, provides one degree-of-freedom of the tool.

[0053] In another embodiment of the invention there is provided aremotely controlled surgical instrument system that is adapted to beinserted through an incision of a patient for operation by a surgeonfrom outside the patient in a remote location, the system comprising: anelongate tube having a proximal end disposed outside the patient and adistal end internal of the patient; a support for the elongate tube thatprovides controlled translation of said elongate tube with the proximalend thereof moving substantially only in a predetermined plane; and theelongate tube having an axis and a tool mounted on a distal end of thetube, the elongate tube being curved along a distal length of theelongate tube and controllably rotatable around the axis such that thetool is movable in a circle or an additional two degrees of freedominternal of the patient by rotation of the arm member.

[0054] These and other features of the invention are described in thefollowing detailed description.

Portability

[0055] Another aspect of the invention is to provide readily manuallyportable components positionable in close proximity to a patient withinthe sterile field, without unduly reducing access to the patient orotherwise interfering with the procedure.

[0056] In one embodiment, a portable remotely controllable surgicalinstrument is provided including a shaft, a mounting mechanism and adrive unit. A manually portable elongated shaft is provided having aproximal end and a distal end manually positionable at an operative sitewithin a subject upon insertion of the shaft through an incision in thesubject. A manually portable mounting mechanism is readily manuallymountable in a fixed position outside the patient through the incision,the proximal end of the portable shaft being mounted thereon. A manuallyportable drive unit is drivably interconnected through the mountingmechanism to a tool mounted at the distal end of the portable shaft. Thedrive unit is readily manually positionable at a selected positionoutside the patient.

[0057] In various embodiments, the drive unit is controllably drivableby a computer. The proximal end of the portable shaft is readilymanually mountable on the portable mounting mechanism for enablingreadily drivable intercoupling of the tool to the drive unit. Theportable shaft may be disposable. The drive unit may be readily manuallymountable at a position remote from the incision.

[0058] In another embodiment, there is provided a portable remotelycontrollable surgical apparatus comprising: a manually portableelongated shaft having a proximal end and a distal end manuallypositionable at an operative site within a subject upon insertion of theshaft through an incision in the subject; a manually portable mountingmechanism being readily manually mountable in a fixed position outsidethe patient near the incision, the proximal end of the portableelongated shaft being mounted thereon; a manually portable support forfixedly positioning the manually portable mounting mechanism in aselected location relative to the subject, the manually portable supportbeing readily fixedly attachable to and detachable from a stationarystructure on or relative to which the subject is mounted. A portabledrive unit is preferably drivably intercoupled through the mountingmechanism to a tool mounted at the distal end of the portable shaft;wherein the drive unit is readily positionable at a selected positionoutside and remote from the incision. The surgical instrument mayinclude one or more mechanically drivable components drivablyintercoupled to a drive unit, the apparatus further comprisingmechanical cabling drivably coupled to the one or more components at oneend of the cabling, the mechanical cabling being readily drivablycouplable to and decouplable from the drive unit at another end of themechanical cabling.

[0059] In another embodiment there is provided a portable remotelycontrollable surgical apparatus comprising: a manually portableelongated shaft having a proximal end and a distal end manuallypositionable at an operative site within a subject upon insertion of theshaft through an incision in the subject; a manually portable mountingmechanism being readily manually mountable in a fixed position outsidethe patient near the incision, the proximal end of the portableelongated shaft being mounted thereon; a portable drive unit drivablyinterconnected to the portable elongated shaft through the mountingmechanism; mechanical cabling drivably coupled to the mounting mechanismat one end of the cabling and readily drivably couplable to anddecouplable from the portable drive unit at another end of the cabling.The mounting mechanism typically includes one or more mechanicallydrivable components for moving the mounting mechanism outside thesubject, the one or more mechanically drivable components being drivablyinterconnected to the drive unit through the mechanical cabling.

[0060] These and other features of the invention are set forth ingreater detail in the following detailed description section.

User Control Apparatus

[0061] Another aspect of the invention is to provide, in a master/slavesurgery system, a master station which includes upper and lowerpositioner assemblies, movably connected, including an arm assembly witha distal hand assembly for engagement by the surgeon's hand.

[0062] In one embodiment, a master station is adapted to be manuallymanipulated by a surgeon to, in turn, control motion to a slave stationat which is disposed a surgical instrument. The master station includesa lower positioner assembly, an upper positioner assembly and an armassembly. The upper positioner assembly is supported over and inrotational engagement with the lower positioner assembly to enable alateral side-to-side surgical manipulation. An arm assembly has at itsdistal end a hand assembly for engagement by a surgeon's hand, and aproximal end pivotally supported from the upper positioner assembly toenable an orthogonal forward and back surgeon manipulation in adirection substantially orthogonal to the lateral surgeon manipulation.

[0063] In various preferred embodiments, the arm assembly includes aproximal arm member and a distal arm member joined by a rotationaljoint. A position encoder is disposed at a rotational joint detectsrotation of the distal arm member. A pivotal joint connects the handassembly to the distal end of the distal arm member, this movement beingresponsive to a pivotal movement of a surgeon's wrist.

[0064] The hand assembly may include a base piece with a pair of holderscoupled with a base piece. One of these holder is adapted to receive athumb and the other adapted to hold a forefinger. Each holder maycomprise a metal bar positioned along the thumb or forefinger and aVelcro loop for attaching the thumb or finger to the bar. The handassembly may further include a pair of rotating element pivotallysupported from opposite ends of the base piece. One of these holders issecured to one of the rotating elements so that the surgeon can move oneholder toward and away from the other holder. The pivotal joint thatconnects the hand assembly to the distal end of the distal arm isconnected to the other rotating element, to account for rotationalmotion at the surgeon's wrist.

[0065] In another embodiment, a master station of a master/slave surgerysystem includes a base, an arm assembly pivotally supported from thebase, and a hand assembly pivotally supported from the arm assembly,wherein the hand assembly includes a finger holder and a thumb holderand wherein the holders are supported for relative movementtherebetween. The hand assembly may include a base piece for theholders, wherein the thumb holder is fixed in position relative to abase piece and the finger holder rotates from the base piece.

[0066] In another embodiment, a master station of a master/slave surgerysystem includes a base, an arm assembly pivotally supported from thebase, and a hand assembly pivotally supported from the arm assembly, thehand assembly including a guide shaft adapted to be grasped by thesurgeon, an actuator on the guide shaft, and a multiple rotation jointattaching the guide shaft to the arm assembly.

[0067] In yet another embodiment, a template is provided secured to thesupport which holds the surgical instrument, for locating the positionof the support and subsequently the position of the surgical instrument,relative to the incision point of the patient. This enables an accurateplacement of the instrument at an operative site internal to thepatient.

[0068] These and other features of the present invention are describedin greater detail in the following detailed description section.

Electronic Controls and Methodology

[0069] The invention also provides a method of controlling a surgicalinstrument that is inserted in a patient for facilitating a surgicalprocedure and controlled remotely from an input device manipulated by asurgeon at a user interface, the method comprising the steps of:initializing the position of the surgical instrument without calculatingits original position, and the position of the input device underelectronic control; the initializing including establishing an initialreference position for the input device and an initial referenceposition for the surgical instrument; calculating the current absoluteposition of the input device as it is manipulated by the surgeon;determining the desired position of the surgical instrument based upon:the current position of the input device, the reference position of theinput device, and the reference position of the surgical instrument, andmoving the surgical instrument to the desired position so that theposition of the surgical instrument corresponds to that of the inputdevice. The input device typically has position sensors, and the step ofinitializing includes initializing these position sensors. Theinitializing is preferably to zero. The method may include computing aninitial reference orientation for the input device, computing a desiredorientation for the surgical instrument and/or computing a desiredposition for the surgical instrument. The initializing step may includeperforming a forward kinematic computation from the input device. Themethod may include reading position sensor values and current time. Thecalculating step may include calculating both the position andorientation of the input device. The method may further includecalculating the current orientation of the input device. The step ofdetermining may include performing an inverse kinematic computationand/or a transformation into an earth coordinate system From thetransformation determined joint angles and drive motor angles for thesurgical instrument orientation may be determined.

[0070] In another embodiment, there is provided a method of controllinga tool of a surgical instrument that is inserted in a patient forcarrying out a surgical procedure and is controlled remotely by way of acontroller from an input device at a user interface, the methodcomprising the steps of: the input device at an initial referenceconfiguration and under controller control; setting the surgicalinstrument in the patient at an initial predefined referenceconfiguration without controller control; calculating the currentabsolute position of the input device; determining the desired locationof the tool by a kinematic computation that accounts for at least theinitial reference configuration of the input device and the currentabsolute position of the input device; and moving the surgicalinstrument to the desired position so that the location of the toolcorresponds to that of the input device. The step of determining mayalso be based upon the initial reference configuration of the tool.

[0071] In another embodiment, there is provided a system for controllingan instrument that is inserted in a patient to enable a surgicalprocedure and controlled remotely from an input device controlled by asurgeon at a user interface, the system comprising: a base; a first linkrotatably connected to the base; an elbow joint for rotatably connectingthe second link to the first link; a handle; a wrist member connectingthe handle to the distal end of the second link; and a controllercoupled to at least the base and links and for receiving signalsrepresentative of: a rotational position of the base, a rotationalposition of the first link relative to the base, and a rotationalposition of the second link relative to the first link.

[0072] In another embodiment, there is provided a control system for aninstrument that is controlled remotely from an input device, the systemcomprising: a forward kinematics block for computing the position of theinput device; an initialization block for storing an initial referenceposition of the input device; an inverse kinematics block coupled fromthe forward kinematics block and the initialization block for receivinginformation from the forward kinetics block of the current input deviceposition; and a controller block coupled from the inverse kinematicsblock for controlling the position of the instrument in response tomanipulations at the input device. Such a control system may include ascaling block coupled between the forward kinematics block and theinverse kinematics block for scaling motions imparted at the inputdevice. The system may also include an output from the forwardkinematics block directly to the inverse kinematics block representativeof current input device orientation. The system may also include acombining device coupled from the forward kinematics block and theinitialization block to the scaling block for providing a signal to theinverse kinematics block representative of desired instrument position.The input device typically includes a wrist and a handle and theposition of the wrist is expressed in x, y and z coordinates. Theorientation of the handle is typically determined by a series ofcoordinate transformations. Such system may include a transformationmatrix for the handle coordinate frame with respect to a referencecoordinate frame, a transformation matrix R_(wh) for the wrist jointcoordinate with respect to a reference coordinate, and a transformationmatrix R_(hwh) for the handle coordinate with respect to the wristcoordinate. The transformation matrix R_(h) for the handle coordinatewith respect to the reference coordinate may be R_(h)=R_(wh) R_(hwh).

[0073] In another embodiment there is provided a method of controlling amedical implement remotely from an input device that is controlled by anoperator, the method comprising the steps of positioning the medicalimplement at an initial start position at an operative site for thepurpose of facilitating a medical procedure; establishing a fixedposition reference coordinate representative of the initial startposition of the medical implement based upon a base point of theimplement and an active point of the implement being in a known relativedimensional configuration, positioning the input device at an initialstart position; establishing a fixed position reference coordinaterepresentative of the initial start position of the input device;calculating the current position of the input device as it iscontrolled; determining the desired position of the medical implementbased upon; the current position of the input device, the fixed positionreference coordinate of the input device, and the fixed positionreference coordinate of the medical implement, and moving the medicalimplement to the desired position so that the position of the medicalimplement corresponds to that of the input device.

[0074] In another embodiment there is provided a method of controlling asurgical instrument remotely from an input device and by way of anelectronic controller, the method comprising the steps of: inserting thesurgical instrument through an incision in the patient so as to disposethe distal end of the instrument at an initial start position;establishing a fixed position reference coordinate system correspondingto a fixed known position on the surgical instrument at the initialstart position of the surgical instrument; positioning the input deviceat an initial start position; establishing a fixed position referencecoordinate system representative of the initial start position of theinput device; calculating the current absolute position of the inputdevice as it is controlled; determining the desired position of thesurgical instrument based upon the current absolute position of theinput device, and the fixed position reference coordinate system for therespective surgical instrument and input device; and moving the surgicalinstrument to the desired position so that the position of the surgicalinstrument corresponds to that of the input device.

[0075] The invention also provides a program of instructions for theprocessor which include: receiving an insertion length of a medicalinstrument inserted in a patient; and determining a distal end locationof the instrument at a target site in the patient from the insertionlength. The instrument typically has a straight proximal portion andcurved distal portion, lies in a single plane and is a rigid guidemember. The instrument is typically inserted and then fixed at a pivotaxis outside the patient. The pivot axis is generally aligned with aninsertion point at which the instrument is inserted into the patient.The program of instructions may include determining a subsequentlocation of the distal end associated with pivoting about the pivotaxis. The program of instructions may include determining a subsequentlocation of the distal end associated with axial rotation of theinstrument, determining a subsequent location of the distal endassociated with linear translation along a length axis of the instrumentand/or determining a subsequent movement of the distal end in a singleplane about the pivot axis. The pivotal axis is typically a referencepoint used by the program of instructions in determining subsequentmovement of the distal end.

[0076] The invention also provides a processor and a memory devicecontaining a program of instructions for the processor which include:receiving a coordinate representative of the desired location of thedistal end of a medical instrument at a target site in a patient; anddetermining from the coordinate an insertion length for the medicalinstrument so as to locate the distal end at the target site.

[0077] These and other features of the present invention are describedin greater detail in the following detailed description section.

DESCRIPTION OF DRAWINGS

[0078]FIG. 1 is a perspective view illustrating one embodiment of therobotic system of the present invention;

[0079] FIGS. 1A-1C are three views of a flexible cannula for use withthe embodiment of FIG. 1;

[0080]FIG. 2A is a schematic diagram illustrating the degrees-of-freedomassociated with the master station;

[0081]FIG. 2B is a schematic diagram illustrating the degrees-of-freedomassociated with the slave station;

[0082]FIG. 2C shows a functional schematic diagram of the surgicaladapter component of the system of FIG. 1;

[0083]FIG. 2D shows a functional schematic diagram of the instrumentinsert component of the system of FIG. 1;

[0084]FIG. 3 is a perspective view of the positioner assembly at themaster station;

[0085]FIG. 4 is an exploded perspective view also of the positionerassembly at the master station;

[0086]FIG. 5 is a partially exploded view of the hand assembly portionassociated with the positioner assembly;

[0087]FIG. 6 is a cross-sectional view of the hand assembly as takenalong line 6-6 of FIG. 3;

[0088]FIG. 7 is a cross-sectional view at the master station as takenalong lines 7-7 of FIG. 3;

[0089]FIG. 7A is a schematic perspective view of the yoke assemblyportion of the positioner assembly;

[0090]FIG. 8 is a perspective view of the slave station;

[0091]FIG. 8A is a perspective view of an alternative adjustable clampmember at the slave station;

[0092]FIG. 8B is a top plan view of the clamp of FIG. 8A;

[0093]FIG. 8C is a side view of the clamp of FIGS. 8A and 8B as takenalong line 8C-8C of FIG. 8B;

[0094]FIG. 8D is a perspective view of a template used with thisembodiment;

[0095]FIG. 8E is a schematic cabling diagram illustrating one cablearrangement used to operate a tool;

[0096]FIG. 8F is an exploded perspective view of another version of thecable drive mechanism and tool in accordance with the present invention;

[0097]FIG. 8G is a schematic perspective view similar to thatillustrated in FIG. 8F but specifically showing the cablingconstruction;

[0098]FIG. 8H is a partially broken away front elevational view as takenalong line 8H-8H of FIG. 8F;

[0099]FIG. 8I is a top plan cross-sectional view taken along line 8I-8Iof FIG. 8H;

[0100]FIG. 8J is a further cross-sectional top plan view as taken alongline 8J-8J of FIG. 8H,

[0101]FIG. 8K is a cross-sectional side view as taken along line 8K-8Kof FIG. 8H;

[0102]FIG. 8L is a cross-sectional rear view of the coupler spindle anddisk as taken along line 8L-8L of FIG. 8K.

[0103]FIG. 9 is a view at the slave station taken along line 9-9 of FIG.8;

[0104]FIG. 10 is a side elevation view at the slave station taken alongline 10-10 of FIG. 9;

[0105]FIG. 11 is a perspective view at the slave station;

[0106]FIG. 11A is a cross-sectional view as taken along line 11A-11A ofFIG. 11;

[0107]FIG. 11B is a cross-sectional view as taken along line 11B-11B ofFIG. 11A;

[0108]FIG. 11C is a cross-sectional view as taken along line 11C-11C ofFIG. 11A;

[0109]FIG. 12 is a cross-sectional view as taken along line 12-12 ofFIG. 11;

[0110]FIG. 13 is a cross-sectional view as taken along line 13-13 ofFIG. 12;

[0111]FIG. 14 is a cross-sectional view as taken along line 14-14 ofFIG. 12;

[0112]FIG. 15 is a perspective view at the slave station showing theinstrument insert being removed from the adapter;

[0113]FIG. 15A is a top plan view of the instrument insert itself;

[0114]FIG. 16A is a perspective view at the tool as viewed along line16A-16A of FIG. 11;

[0115]FIG. 16B is an exploded perspective view ofthe tool of FIG. 16A;

[0116]FIG. 16C is a fragmentary perspective view of an alternative toolreferred to as a needle driver;

[0117]FIG. 16D is a side elevation view of the needle driver of FIG.16C;

[0118]FIG. 16E is a perspective view of an alternate embodiment of thetool and wrist construction;

[0119]FIG. 16F is an exploded perspective view of the constructionillustrated in FIG. 16E;

[0120]FIG. 16G is a fragmentary perspective view showing a portion ofthe bending section;

[0121]FIG. 16H is a plan view of the flexible wrist member associatedwith the construction of FIGS. 16E-16G.

[0122]FIG. 16I is a perspective view of still another embodiment of aflexible end tool;

[0123]FIG. 16J is an exploded perspective view of the constructionillustrated in FIG. 16I;

[0124]FIG. 16K is a fragmentary perspective view showing further detailsof the bending section;

[0125]FIG. 17 is a perspective view of the drive unit at the slavestation;

[0126]FIG. 17A is a schematic front view of the drive unit at the slavestation;

[0127]FIG. 18 is a schematic perspective view of an alternative handpiece for use at the master station;

[0128] FIGS. 19A-19D are schematic diagrams showing alternate positionsof the guide tube of the adapter;

[0129]FIG. 20 is a block diagram of the controller used with the roboticsystem of this embodiment;

[0130]FIG. 21 is a block diagram of further details of the controller,including the module board;

[0131]FIG. 22 is a block diagram of a control algorithm in accordancewith the present embodiment; and

[0132] FIGS. 23-28 are a series of schematic diagrams of the inputdevice position and resulting instrument position relating to thealgorithm control of the present embodiment.

DETAILED DESCRIPTION A. Overview of Surgical Robotic System (FIGS. 1-2)

[0133] An embodiment of a surgical robotic system of the presentinvention is illustrated in the accompanying drawings. The describedembodiment is preferably used to perform minimally invasive surgery, butmay also be used for other procedures such as endoscopic or opensurgical procedures.

[0134]FIG. 1 illustrates a surgical instrument system 10 that includes amaster station M at which a surgeon 2 manipulates a pair of inputdevices 3, and a slave station S at which is disposed a pair of surgicalinstruments 14. The surgeon is seated in a comfortable chair 4 with hisforearms resting upon armrests 5. His hands manipulate the input devices3 which cause a responsive movement of the surgical instruments 14.

[0135] A master assembly 7 is associated with the master station M and aslave assembly 8 is associated with the slave station S. Assemblies 7and 8 are interconnected by cabling 6 to a controller 9. Controller 9has one or more display screens enabling the surgeon to view a targetoperative site, at which is disposed a pair of tools 18. The controllerfurther includes a keyboard for inputting commands or data.

[0136] As shown in FIG. 1, the slave assembly 8, also referred to as adrive unit, is remote from the operative site and is positioned outsideof the sterile field. In this embodiment, the sterile field is definedabove the plane of the top surface of the operating table T, on which isplaced the patient P. The drive unit 8 is controlled by a computersystem, part of the controller 9. The master station M may also bereferred to as a user interface, whereby commands issued at the userinterface are translated by the computer into an electrical signalreceived by drive unit 8. Each surgical instrument 14, which is tetheredto the drive unit 8 through mechanical cabling, produces a desiredresponsive motion.

[0137] Thus, the controller 9 couples the master station M and the slavestation S and is operated in accordance with a computer program oralgorithm, described in further detail later. The controller receives acommand from the input device 3 and controls the movement of thesurgical instrument in a manner responsive to the input manipulation.

[0138] With further reference to FIG. 1, associated with the patient Pare two separate surgical instruments 14, one on either side of anendoscope 13. The endoscope includes a camera mounted on its distal endto remotely view the operative site. The dashed line circle in FIG. 2B,labeled OS, is an example of the operative site). A second camera may bepositioned away from the site to provide an additional perspective onthe medical procedure or surgical operation. It may be desirable toprovide the endoscope through an orifice or incision other than the oneused by the surgical instrument. Here three separate incisions areshown, two for the surgical instruments 14, 14 and a centrally disposedincision for the viewing endoscope 13. A drape over the patient has asingle opening for the three incisions.

[0139] Each of the two surgical instruments 14 is generally comprised oftwo basic components, an adaptor or guide member 15 and an instrumentinsert or member 16. The adaptor 15 is a mechanical device, driven by anattached cable array from drive unit 8. The insert 16 extends throughthe adaptor 15 and carries at its distal end the surgical tool 18.Detailed descriptions of the adapter and insert are found in laterdrawings.

[0140] Although reference is made to “surgical instrument” it iscontemplated that this invention also applies to other medicalinstruments, not necessarily for surgery. These would include, but arenot limited to catheters and other diagnostic and therapeuticinstruments and implements.

[0141] In FIG. 1 there is illustrated cabling 12 coupling the instrument14 to the drive unit 8. The cabling 12 is readily attachable anddetachable from the drive unit 8. The surgical adaptor 15, whichsupports the instrument at a fixed reference point is of relativelysimple construction and may be designed for a particular surgicalapplication such as abdominal, cardiac, spinal, arthroscopic, sinus,neural, etc. As indicated previously, the instrument insert 16 iscouplable and decouplable to the adaptor 15, and provides a means forexchanging instrument inserts, with then attached tools. The tools mayinclude, for example, forceps, scissors, needle drivers, electrocautery,etc.

[0142] Referring again to FIG. 1, the overall system 10 includes asurgeon's interface 11, computer system or controller 9, drive unit 8and surgical instruments 14. Each surgical instrument 14 is comprised ofan instrument insert 16 extending through adapter 15. During use, asurgeon manipulates the input device 3 at the surgeon's interface 11,which manipulation is interpreted by controller 9 to effect a desiredmotion of the tool 18 within the patient.

[0143] Each surgical instrument 14 is mounted on a separate rigidsupport post 19 which is illustrated in FIG. 1 as removably affixed tothe side of the surgical table T. This mounting arrangement permits theinstrument to remain fixed relative to the patient even if the table isrepositioned. Although two instruments 14 are shown here, the inventioncan be practiced with more or with only a single surgical instrument.

[0144] Each surgical instrument 14 is connected to the drive unit 8 bytwo mechanical cabling (cable-in-conduit) bundles 21 and 22. Thesebundles 21 and 22 terminate at connection modules, illustrated in FIG.8F, which are removably attachable to the drive unit 8. Although twocable bundles are used here, more or fewer cable bundles may be used.Also, the drive unit 8 is preferably located outside the sterile fieldas shown here, although in other embodiments the drive unit may bedraped with a sterile barrier so that it may be located within thesterile field.

[0145] In a preferred technique for setting up the system, a distal endof the surgical instrument 14 is manually inserted into the patientthrough an incision or opening. The instrument 14 is then mounted to therigid post 19 using a mounting bracket 25. The cable bundles 21 and 22are then passed away from the operative area to the drive unit 8. Theconnection modules of the cable bundles are then engaged to the driveunit 8. One or more instrument inserts 16 may then be passed through thesurgical adaptor 15, while the adapter remains fixed in position at theoperative site. The surgical instrument 14 provides a number ofindependent motions, or degrees-of-freedom, to the tool 18. Thesedegrees-of-freedom are provided by both the surgical adaptor 15 and theinstrument insert 16.

[0146] The surgeon's interface 11 is in electrical communication withthe controller 9. This electrical control is primarily by way of thecabling 6 illustrated in FIG. 1 coupling from the master assembly 7.Cabling 6 also couples from the controller 9 to the drive unit 8. Thecabling 6 is electrical cabling. The drive unit 8 however, is inmechanical communication with the instruments 14 in mechanical cabling21, 22. The mechanical communication with the instrument allows theelectromechanical components to be removed from the operative region,and preferably from the sterile field.

[0147]FIG. 2A illustrates the various movements (J1-J7) that occur atthe master station M while FIG. 2B illustrates various movements (J1-J7)that occur at the slave station S. More specific details regarding FIGS.2A and 2B are contained in a later discussion of FIGS. 3-4 (with regardto the master station of FIG. 2A) and FIGS. 8-9 (with regard to theslave station of FIG. 2B).

[0148]FIG. 2C is a simplified representation of adaptor 15 of the slavestation, useful in illustrating the three degrees-of-freedom enabled bythe adapter. The adapter as shown in FIG. 2C comprises a generally rigidouter guide tube 200 (corresponding to guide tube 17 in FIG. 2B) throughwhich an inner flexible shaft, carrying a tool 18 at its distal end, isinserted into the patient. The adapter provides three degrees-of-freedomby way of a pivotal joint J1, a linear joint J2, and a rotary joint J3.From a fixed mounting point 23 shown schematically at the top of FIG.2C, the pivotal joint J1 allows the guide tube 200 to pivot about afixed vertical axis 204, while maintaining the tube (both the proximalstraight portion 208 and distal curved portion 202) in a single plane,transverse to pivot axis 204, in which lies central horizontal tube axis201. The linear joint J2, moves the rigid guide tube 200 along this sameaxis 201. The rotary joint J3 rotates the guide tube 200 about the tubeaxis 201. The guide tube 200 has a fixed curve or bend 202 at its distalend 203; as a result the distal end 203 will orbit in a circle about theaxis 201 when the straight portion 208 of the guide tube 200 is rotatedabout its axis 201. Alternatively, the three degrees-of-freedom can beachieved by a structure other than a curve 202, such as by means of ajoint or angular end section. The point is to have the distal end 203 ofthe tube 200 at a location spaced away from the tube axis 201.

[0149]FIG. 2C thus shows a schematic view of the three degrees offreedom of the rigid curved guide tube 200. In summary, via the pivot205 the guide tube 200 may rotate in a direction J1 about an axis 204.The guide tube 200 may also slide in an axial direction J2 alongproximal tube axis 201 (via the linear slider) and rotate in a directionJ3 about the proximal tube axis 201 (via a rotatable mounting at theguide tube housing). It is intended that the point 205 at which the axesof linear movement and rotation 201 and 204 intersect, be in linearalignment (along axis 204) with the incision point illustrated in dottedoutline at 207, at which the guide tube enters the patient. Positioningthe incision 207 in substantially vertical linear alignment with point205 results in less trauma to the patient in the area around theincision, because movement of the guide tube 17 near the point 205 islimited.

[0150] In addition to the three degrees-of-freedom provided by the guidetube 17, the tool 18 may have three additional degrees-of-freedom. Thisis illustrated schematically in FIG. 2D which shows an inner flexibleshaft 309, fixed at its proximal end 300, having a straight proximalportion 301 and having a curved distal portion 302 with a tool 18mounted at the distal end. The shaft 309 has a wrist joint that rotatesabout axis 306. A pair of pinchers 304, 305 independently rotate asshown (J6 and J7) about horizontal axis 308 to open and close (e.g., tograsp objects). Still further, the inner shaft can be rotated (J4) aboutthe central axis of proximal portion 301.

[0151] In practice, an instrument insert 16 (carrying the inner shaft309) is positioned within the adaptor 15 (including guide tube 17), sothat the movements of the insert are added to those of the adaptor. Thetool 18 at the distal end of insert 16 has two end grips 304 and 305,which are rotatably coupled to wrist link 303, by two rotary joints J6and J7. The axis 308 of the joints J6 and J7 are essentially collinear.The wrist link 303 is coupled to a flexible inner shaft 302 through arotary joint J5, whose axis 306 is essentially orthogonal to the axis308 of joints J6 and J7. The inner shaft 309 may have portions ofdiffering flexibility, with distal shaft portion 302 being more flexiblethan proximal shaft portion 301. The more rigid shaft portion 301 isrotatably coupled by joint J4 to the instrument insert base 300. Theaxis of joint J4 is essentially co-axial with the rigid shaft 301.Alternatively, the portions 301 and 302 may both be flexible.

[0152] Through the combination of movements J1-J3 shown in FIG. 2C, theadaptor 15 can position the curved distal end 203 of guide tube 200 toany desired position in three-dimensional space. By using only a singlepivotal motion (J1), the motion of the adaptor 15 is limited to a singleplane. Furthermore, the fixed pivot axis 204 and the longitudinal axis201 intersect at a fixed point 205. At this fixed point 205, the lateralmotion of the guide tube 200 is minimal, thus minimizing trauma to thepatient at the aligned incision point 207.

[0153] The combination of joints J4-J7 shown in FIG. 2D allow theinstrument insert 16 to be actuated with four degrees-of-freedom. Whencoupled to the adaptor 15, the insert and adaptor provide the instrument14 with seven degrees-of-freedom. Although four degrees-of-freedom aredescribed here for the insert 16, it is understood that greater andfewer numbers of degrees-of-freedom are possible with differentinstrument inserts. For example an energized insert with only onegripper may be useful for electro-surgery applications, while an insertwith an additional linear motion may provide stapling capability.

[0154]FIG. 2B shows in dotted outline a cannula 487, through which theguide tube 17 is inserted at the incision point. Further details of thecannula are illustrated in FIGS. 1A-1C. FIG. 1A is a longitudinalcross-sectional view showing a cannula 180 in position relative to, forexample, an abdominal wall 190 of the patient. FIG. 1B is a schematicview of the guide tube 17 being inserted through the flexible cannula180. FIG. 1C is a schematic view of the guide tube inserted so that theproximal straight section of the tube is positioned at the incisionpoint within the cannula, with the curved distal end of the guide tubeand tool 18 disposed at a target or operative site.

[0155] The cannula 180 includes a rigid base 182 and a flexible end orstem 184. The base may be constructed of a rigid plastic or metalmaterial, while the stem may be constructed of a flexible plasticmaterial having a fluted effect as illustrated in FIGS. 1A-1C. Thelength of the base is short enough that the curve in the guide tube caneasily pass through a center passage or bore 186 in the base 182. Thebore 186 has a larger diameter than the outer diameter of the guide tube17 to facilitate passage of the guide tube through the cannula 180. Adiaphragm or valve 188 seals the guide tube 17 within the cannula 180.

[0156]FIG. 1A shows a cap 192 secured to the proximal end of the base182 by one or more o-rings 194. Before the guide tube 17 is inserted incannula 180, a plug 196 may be inserted to seal the proximal end of thebase 182. The plug 196 is secured by a tether 198 to base 182.

[0157] In the context of an insertable instrument system, there maygenerally be distinguished two types of systems, flexible and rigid. Aflexible system would use a flexible shaft, which may be defined as ashaft atraumatically insertable in a body orifice or vessel which issufficiently pliable that it can follow the contours of the body orificeor vessel without causing significant damage to the orifice or vessel.The shaft may have transitions of stiffness along its length, either dueto the inherent characteristics of the material comprising the shaft, orby providing controllable bending points along the shaft. For example,it may be desirable to induce a bend at some point along the length ofthe shaft to make it easier to negotiate a turn in the body orifice. Amechanical bending of the tube may be caused by providing one or moremechanically activatable elements along the shaft at the desired bendingpoint, which a user remotely operates to induce the bending upon demand.The flexible tube may also be caused to bend by engagement with a bodyportion of greater stiffness, which may, for example, cause the tube tobend or loop around when it contacts the more stiffer body portion.Another way to introduce a bend in the flexible shaft is to provide amechanical joint, such as the wrist joint provided adjacent to tool 18as previously described, which, as discussed further, is mechanicallyactuated by mechanical cabling extending from a drive unit to the wristjoint.

[0158] One potential difficulty with flexible shafts or tubes as justdescribed is that it can be difficult to determine the location of anyspecific portion or the distal end of such shaft or tube within thepatient. In contrast, what is referred to as a rigid system may utilizea rigid guide tube 17 as previously described, for which the position ofthe distal end is more easily determined, simply based upon knowing therelevant dimensions of the tube. Thus, in the system previouslydescribed, a fixed pivot point (205 in FIG. 2C) is aligned with anincision point 207. One can determine the position of the rigid guidetube 17, knowing the length from the fixed point to the distal end ofthe guide tube, which is fixed and predetermined based upon the rigidnature of the guide tube, and the known curvature of the distal end ofthe guide tube. The point of entry or incision point serves as a pivotpoint, for which rotation J1 of the guide tube about the fixed axes 204is limited to maintaining the proximal end of the guide tube in a singleplane.

[0159] Furthermore, by inserting the more flexible shaft, carrying atool 18 at its distal end, within the rigid guide tube, the rigid guidetube in effect defines a location of the flexible shaft and its distalend location tool 18.

[0160] Also relevant to the present invention is the use of the term“telerobotic” instrument system, in which a physician or medicaloperator is manually manipulating some type of hand tool, such as a joystick, and at the same time is looking at the effect of such manualmanipulation on a tool which is shown on a display screen, such as atelevision or a video display screen, accessible to the operator. Theoperator then can adjust his manual movements in response to visualfeedback he receives by viewing the resulting effect on the tool, shaftguide tube, or the like, shown on the display screen. It is understoodthat the translation of the doctor's manual movement, via a computerprocessor which feeds a drive unit for the inserted instrument, is notlimited to a proportional movement, rather, the movement may be scaledby various amounts, either in a linear fashion or a nonlinear fashion.The scaling factor may depend on where the instrument is located orwhere a specific portion of the instrument is located, or upon therelative rate of movement by the operator. The computer controlledmovement of the guide tube or insert shaft in accordance with thepresent invention, enables a higher precision or finer control over themovement of the instrument components within the patient.

[0161] In practice, the physician, surgeon or medical operator wouldmake an incision point, inserting the flexible cannula previously shown.He would then manually insert the rigid curved guide tube until thedistal point of the guide tube was positioned at the operative site.With the guide tube aligned in a single plane, the operator would clampthe guide tube at the support bracket 25 on post 19, to establish thefixed reference pivot point, (205 in FIG. 2C), with the incision pointaxially aligned under the fixed pivot point. The operator would thenmanually insert the instrument insert through the guide tube until thetool 18 is extended out from the distal end of the guide tube. The wristjoint on the inner insert shaft is then positioned at a known point,based upon the known length and curvature of the rigid guide tube anddistance along that length at which the incision point is disposed.Then, a physician, surgeon or medical operator located at the masterstation can manually adjust the hand assembly to cause a responsivemovement of the inserted instrument. The computer control decides whatthe responsive movement at the instrument is, including one or more ofmovement of the guide tube, the whole instrument 14, or the flexibleinner shaft or the tool at its distal end. A pivotal movement J1 willrotate the proximal end of the guide tube, causing pivoting of the wholeinstrument 14. An axial movement J2 of the whole instrument 14 willreposition the instrument in the single plane. A rotational movement J3of just the guide tube results in the end of the guide tube and end ofthe inner shaft being taken out of the plane, following a circular pathor orbit in accordance with rotation of the guide tube shaft. Thesethree movements J1, J2 and J3 are defined as setting the position of thewrist joint 303 of the tool.

[0162] The other three movements J4-J7, are defined as setting theorientation of the instrument insert, and more specifically, a directionat which the tool is disposed with respect to the wrist joint. Centralmechanical cables in the inner shaft cause motions J5-J7, J5 being thewrist movement and J6-J7 being the jaw movement of the tool. The J4movement is for rotation of the inner shaft by its proximal axis, withinthe guide tube. These relative movements, and the position andorientation of the instrument insert, will be further described in alater discussion of an example of the computer algorithm for translatingthe movement at the master station to a movement at the slave station.

B. The Master Station M (FIGS. 3-7)

[0163] At the master station M illustrated in FIG. 1 and shown infurther detail in FIG. 3, there are two sets of identical hand controls,one associated with each hand of the surgeon. The outputs of bothcontrols are fed to assembly 7, which is secured to the surgeon's chair4 by a cross-brace 40. In FIG. 3, the brace 40 is shown secured to thechair frame 42 by means of adaptor plate 44 and bolts 45. Additionalbolts 46, with associated nuts and washers secure the cross-brace 40 ina desired lateral alignment (see double headed arrow) along the adaptorplate 44. Additional bolts 49 (see FIG. 4) are used for securing thecross-brace 40 with a base piece 48. The base piece 48 supports lowerand upper positioner assemblies, as will now be described.

[0164] A lower positioner assembly 50 is supported from the base piece48. An upper positioner assembly 60 is supported above and in rotationalengagement (see arrow J1 in FIGS. 2A and 4), in a substantiallyhorizontal plane with the lower positioner assembly. This rotationalmovement J1 enables a lateral or side-to-side manipulation by thesurgeon. An arm assembly 90, having a lower proximal end 90A, ispivotally supported (J2) from the upper positioner assembly 60 about asubstantially horizontal axis 60A (see FIGS. 2A and 3) to enablesubstantially vertical surgeon manipulation. The arm assembly 90 has anupper distal end 90B (FIG. 3), carrying a hand assembly 110.

[0165] As shown in FIG. 4, the lower positioner assembly 50 includes abase member 51 that is secured to the base piece 48 by bolts 52. It alsoincludes a bracket 53 that is secured to the base member 51 by means ofbolts 54. The bracket 53 supports a motor/encoder 55. A vertical shaft56 that extends from the upper positioner assembly 60 to the base member51, extends through a passage in the base member 51 and is secured to apulley 57 disposed under the base member 51. A belt 58 engages withpulley 57 and with a further pulley 62 supported from the bracket 53.This further pulley 62 is on a shaft that engages a pulley 59. A furtherbelt 61 intercouples pulley 59 to the shaft of the motor/encoder 55.

[0166] In FIGS. 3 and 4, the base member 51 and bracket 53 arestationary; however, upon rotation about J1, drive is applied to thepulleys 57 and 59 thus applying drive to the motor/encoder 55. Thisdetects the position and movement from one position to another of theupper positioner assembly 60 relative to the lower positioner assembly50.

[0167] The upper positioner assembly 60 has a main support bracket 63,supporting on either side thereof side support brackets 64 and 66. Sidebracket 64 supports a pulley 65, while side bracket 66 supports a pulley67. Above pulley 65 is another pulley 70, while above pulley 67 isanother pulley 72. Pulley 70 is supported on shaft 71, while pulley 72is supported on shaft 73.

[0168] Also supported from side support bracket 64 is anothermotor/encoder 74, disposed on one side of the main support bracket 63.On the other side of bracket 63 is another motor/encoder 76, supportedfrom side support bracket 66. Motor/encoder 74 is coupled to the shaft71 by pulleys 65 and 70 and associated belts, such as the belt 75disposed about pulley 65. Similarly, motor/encoder 76 detects rotationof the shaft 73 through pulleys 67 and 72 by way of two other belts. Thepulley 65 is also supported on a shaft coupling to pulley 70 supportedby side support bracket 64. A further belt goes about pulley 70 so thereis continuity of rotation from the shaft 71 to the motor/encoder 74.These various belts and pulleys provide a movement reduction ratio of,for example, 15 to 1. This is desirable so that any substantialmovements at the master station are translated as only slight movementsat the slave station, thereby providing a fine and controlled action bythe surgeon.

[0169] Extending upwardly from main support bracket 63, is arm assembly90 which includes a pair of substantially parallel and spaced apartupright proximal arms 91 and 92, forming two sides of a parallelogram.Arm 91 is the main vertical arm, while arm 92 is a tandem or secondaryarm. The bottoms of arms 91 and 92 are captured between side plates 78and 79. The secondary arm 92 is pivotally supported by pin 81 (see FIG.4) from the forward end of the side plates 78 and 79. The main arm 91 isalso pivotally supported between the side plates 78 and 79, but isadapted to rotate with the shaft 71. Thus, any forward and back pivotingJ2 of the arm 91 is sensed through the shaft 71 down to themotor/encoder 74. This movement J2 in FIGS. 2A and 4 translates theforward and rearward motion at the surgeon's shoulder.

[0170] The side plates 78 and 79 pivot on an axis defined by shafts 71and 73. However, the rotation of the plates 78 and 79 are coupled onlyto the shaft 73 so that pivotal rotation, in unison, of the side plates78 and 79 is detected by motor/encoder 76. This action is schematicallyillustrated in FIGS. 2A and 4 by J3. Movement J3 represents an up anddown motion of the surgeon's elbow. A counterweight 80 is secured to themore rear end of the side plates 78 and 79, to counter-balance theweight and force of the arm assembly 90.

[0171] As depicted in FIGS. 3 and 4, the tops of the arms 91 and 92 arepivotally supported in a bracket 94 by two pivot pins 89. The bracket 94also supports a distal arm 96 of the arm assembly 90. The rotation ofdistal arm 96 is sensed by an encoder 88. Thus, the distal arm 96 isfree to rotate J4 about its longitudinal axis, relative to the arms 91and 92. This rotation J4 translates the rotation of the surgeon'sforearm.

[0172] The distal end of distal arm 96 is forked, as indicated at 95 inFIG. 4. The forked end 95 supports disc 97 in a fixed position on shaft98. The disc 97 is fixed in position while the shaft 98 rotates therein;bearings 93 support this rotation. The shaft 98 also supports one end ofpivot member 100, which is part of hand assembly 110. The pivot member100 has at its proximal end a disc 101 that is supported co-axially withthe disc 97, but that rotates relative to the fixed disc 97 (see FIGS. 5and 6). This rotation is sensed by an encoder 99 associated with shaft98. The disc end 101 of the pivot member 100 defines the rotation J5 inFIG. 4, which translates the wrist action of the surgeon, particularlythe up and down wrist action.

[0173] The pivot member 100 has at its other end a disc 103 that rotatesco-axially with a disc end 104 of hand piece 105. There is relativerotation between disc 103 and disc 104 about a pivot pin 106 (see FIGS.4 and 6). This relative rotation between the pivot member 100 and thehand piece 105 is detected by a further encoder 109 associated withdiscs 103 and 104. This action translates lateral or side to side (leftand right) action of the surgeon's hand.

[0174] At the very distal end of the master station is a forefingermember 112 that rotates relative to end 114 of the hand piece 105. Asindicated in FIG. 3, the forefinger piece 112 has a Velcro loop 116 forholding the surgeon's forefinger to the piece 112. Also extending fromthe hand piece 105 is a fixed position thumb piece 118, with anassociated Velcro loop 120. In FIG. 3, motion J7 represents the openingand closing between the surgeon's forefinger and thumb.

[0175] Reference is now made to FIG. 5, which shows expanded details ofthe distal end of the arm assembly. One end of the distal arm 96 couplesto the fork 95; fork 95 supports one end of the pivot member 100. Theencoder 99 detects the position of the pivot member 100 relative to thedistal arm 96. The encoder 109 couples to a shaft adapter 119 anddetects relative displacement between the pivot member 100 and the handpiece 105. The thumb piece 118 is secured to the side piece 125 which,in turn, is secured as part of the hand piece 105. Bolts 126 secure thefinger piece 112 to the rotating disc 130. The distal end encoder 132,with encoding disc 134, detects the relative movement between thesurgeon's thumb and forefinger pieces.

[0176]FIG. 6 shows further details of the distal end of the armassembly. Pivot member 100 is attached to the distal arm 96 and the handpiece 105. Further details are shown relating to the encoder 132 and theencoder disc 134. A shaft 140, intercoupling hand piece 105 and disc130, is supported by a bearing 142. The shaft 106 is also supported by abearing 144.

[0177] The detailed cross-sectional view of FIG. 7 is taken along lines7-7 of FIG. 3. This illustrates the base member 51 with the pulley 57supported thereunder by means of the shaft 56. Also illustrated arebearings 147 about shaft 56 which permit the main support bracket 63 topivot (J1). Pulley 57 rotates therewith and its rotation is coupled tothe encoder 55 for detecting the J1 rotation. FIG. 7 also illustratesthe motor/encoder 76, where the separate dashed portions identify motor76A and encoder 76B.

[0178]FIG. 7 also shows further details of the belt and pulleyarrangement. For simplicity, only the pulley 67 and its associatedsupport is disclosed. Substantially the same construction is used on theother side of the main support bracket 63 for the mounting of theopposite pulley 65. A belt 149 about pulley 72 also engages with pulley153 fixedly supported on the shaft 155. The shaft 155 rotates relativeto the fixed side support bracket 66, by way of bearings 154. The shaft155 supports the pulley 67. A toothed belt 150 is disposed about pulley67 to the smaller pulley 152. The pulley 152 is supported on the shaftof the motor/encoder 76. For the most part all pulleys and beltsdisclosed herein are toothed so that there is positive engagement and noslippage therebetween.

[0179] In order to provide adjustment of the belts 149 and 150,adjusting screws are provided. One set of adjusting screws is shown at157 for adjusting the position of the side support bracket 66 and thusthe belt 149. Also, there are belt adjusting screws 158 associated withsupport plate 159 for adjusting the position of the encoder and thusadjusting the belt 150.

[0180]FIG. 7 also illustrates the pulleys 70 and 72 with theirrespective support shafts 71 and 73. FIG. 7A shows details of thepulleys 70 and 72 and their support structure. The pulley 70 isassociated with motion J2. The pulley 72 is associated with motion J3.The pulley 70 and its associated shaft 71 rotate with the vertical mainshaft or arm 91. The pulley 72 and its associated shaft 73 rotateindependent of the arm 91 and instead rotate with the rotation of theside plates 78 and 79. One end of shaft 71 is secured with the pulley70. The other end of the shaft 71 engages a clamp 161, which clamps theother end of the shaft to the support piece 162 of the main vertical arm91. The shaft 71 is supported for rotation relative to the main supportbracket 63 and the side plates 78, 79 by means of bearings 164.

[0181] The opposite pulley 72 and its shaft 73 are supported so that thepulley 72 rotates with rotation of the yoke formed by side plates 78 and79. A clamp 166 clamps the shaft 73 to the side plate and thus to therotating yoke. This yoke actually rotates with the pin of shaft 73. Forfurther support of the shaft 73, there are also provided bearings 168,one associated with the support bracket 63 and another associated withsupport piece 162.

[0182] Regarding the yoke formed by side plates 78 and 79, at one endthereof is a counterweight 80, as illustrated in FIGS. 4 and 7A. Theother end supports a rotating block 170 (see FIG. 4) that supports thelower end of arm 92 and has oppositely disposed ends of pin 81 rotatablyengaged with that end of the yoke (side plates 78 and 79). Bushings orbearings may be provided to allow free rotation of the bottom end of thearm 92 in the yoke that captures this arm.

[0183] In practice, the following sequence of operations occur at masterstation M. After the instrument 14 has been placed at the properoperative site, the surgeon is seated at the console and presses anactivation button, such as the “enter” button on the keyboard 31 onconsole 9. This causes the arms at the master station to move to apredetermined position where the surgeon can engage thumb and forefingergrips. FIG. 1 shows such an initial location where the arm assemblies 3are essentially pointed forward. This automatic initialization movementis activated by the motors in unit 7 at the master station. Thiscorresponds, in FIG. 2A, to upper arm 96 being essentially horizontaland lower arm 92 being essentially vertical.

[0184] While observing the position of the tools on the video displayscreen 30, the surgeon now positions his hand or hands where they appearto match the position of the respective tool 18 at the operative site(OS in FIG. 2B). Then, the surgeon may again hit the “enter” key. Thisestablishes a reference location for both the slave instrument and themaster controls. This reference location is discussed later with detailsof controller 9 and an algorithm for controlling the operations betweenthe master and slave stations. This reference location is alsoessentially identified as a fixed position relative to the wrist jointat the distal end of distal arm 96 at pin 98 in FIG. 4 (axis 98A in FIG.2A). This is the initial predefined configuration at the master station,definable with three dimensional coordinates.

[0185] Now when the surgeon is ready to carry out the procedure, a thirdkeystroke occurs, which may also be a selection of the “enter” key. Whenthat occurs the motors are activated in the drive unit 8 so that anyfurther movement by the surgeon will initiate a corresponding movementat the slave end of the system.

[0186] Reference is now made to FIG. 18 which is a schematic perspectiveview of an alternate embodiment of an input device or hand assembly860A. Rather than providing separate thumb and forefinger members, asillustrated previously, the surgeon's hand is holding a guide shaft861A. On the shaft 861 there is provided a push-button 866A thatactivates an encoder 868A. The guide shaft 861A may be considered moresimilar to an actual surgical instrument intended to be handled directlyby the surgeon in performing unassisted nonrobotic surgery. Thus, thehand piece 860A illustrated in FIG. 18 may be more advantageous to usefor some types of operative procedures.

[0187]FIG. 18 illustrates, in addition to the encoder 868A, three otherencoder blocks, 862A, 863A and 864A. These are schematically illustratedas being intercoupled by joints 870A and 871A. All four of theseencoders would provide the same joint movements depicted previously inconnection with joints J4-J7. For example, the button 866A may beactivated by the surgeon to open and close the jaws.

C. The Slave Station S C1—Slave Overview (FIGS. 8-8D)

[0188] Reference is now made to FIG. 8 which is a perspective viewillustrating the present embodiment of the slave station S. A section ofthe surgical tabletop T is shown, from which extends the rigid angledpost 19 that supports the surgical instrument 14 at mounting bracket 25.The drive unit 8 is also supported from the side of the tabletop by anL-shaped brace 210 that carries an attaching member 212. The brace issuitably secured to the table T and the drive unit 8 is secured to theattaching member 212 by means of a clamp 214. A lower vertical arm 19Aof the rigid support rod 19 is secured to the attaching member 212 byanother clamping mechanism 216, which mechanism 216 permits verticaladjustment of the rigid support 19 and attached instrument 14.Horizontal adjustment of the surgical instrument is possible by slidingthe mounting bracket 25 along an upper horizontal arm 19B of the supportrod 19. One embodiment of the drive unit 8 is described in furtherdetail in FIG. 17. A preferred embodiment is illustrated in FIGS. 8F-8L.

[0189] The clamping bracket 216 has a knob 213 that can be loosened toreposition the support rod 19 and tightened to hold the support rod 19in the desired position. The support rod 19, at its vertical arm 19A,essentially moves up and down through the clamp 216. Similarly, themounting bracket 25 can move along the horizontal arm 19B of the supportrod 19, and be secured at different positions therealong. The clamp 214,which supports the drive unit 8 on the operating table, also has a knob215 which can be loosened to enable the drive unit to be moved todifferent positions along the attaching member 212.

[0190]FIG. 8 also shows the cable-in-conduit bundles 21 and 22. Thecables in the bundle 21 primarily control the action of the adapter orguide member 15. The cables in bundle 22 primarily control the tool 18,all described in further detail below.

[0191]FIG. 8 also illustrates a support yoke 220 to which is secured themounting bracket 25, a pivot piece 222, and support rails 224 for acarriage 226. Piece 222 pivots relative to the support yoke 220 aboutpivot pin 225.

[0192]FIG. 2B is a schematic representation of the joint movementsassociated with the slave station S. The first joint movement J1represents a pivoting of the instrument 14 about pivot pin 225 at axis225A. The second joint movement J2 is a transition of the carriage 226on the rails 224, which essentially moves the carriage and instrument 14supported therefrom, in the direction indicated by the arrow 227. Thisis a movement toward and away from the operative site OS. Both of thesemovements J1 and J2 are controlled by cabling in bundle 21 in order toplace the distal end of the guide tube 17 at the operative site. Theoperative site is defined as the general area in proximity to wheremovement of the tool 18 occurs, usually in the viewing area of theendoscope and away from the incision.

[0193]FIG. 8 also shows a coupler 230 pivotally coupled from a basepiece 234 by means of a pivot pin 232. The coupler 230 is for engagingwith and supporting the proximal end of the instrument insert 16.

[0194] Reference is now made to FIGS. 8A, 8B and 8C which areperspective views of a preferred clamping arrangement which allows alimited amount of pivoting of the mounting bracket 25 (which supportsinstrument 14). The mounting bracket 25 includes a securing knob 450that clamps the mounting bracket 25 to a base 452. The mounting bracketis basically two pieces 455 and 457. A bottom piece 457 is adapted toreceive the upper arm of rigid supporting rod 19 (see FIG. 8B) and issecured thereto by a bolt 458. A top piece 455 is pivotably adjustablerelative to the bottom piece 457 by means of slots 460 that engage withbolts 462. When bolts 462 are loosened, the top piece 455 may be rotatedrelative to the bottom piece 457 so that the instrument 14 may be heldin different positions. The bolts 462 may then be tightened when theinstrument 14 is in a desired angular position.

[0195] An adjustable bracket 25 and support post 19 may be provided ateach side of the table for mounting a surgical instrument 14 on both theleft and the right sides of the table. Depending upon the particularsurgical procedure, it may be desirable to orient a pair of guide tubeson the left and right sides in different arrangements. In thearrangement of FIG. 1, the guide tubes 17, 17 are arranged so that therespective tools 18, 18 face each other. However, for other proceduresit may be desirable to dispose the guides in different positions,allowed by the adjustability of brackets 25, 25 on their respectivesupport posts 19, 19.

[0196]FIG. 8D shows a template 470 useful in a preferred procedure forpositioning the guide tube. In this procedure, when the support post 19is initially positioned, the mounting bracket 25 holds the template 470(rather than the instrument 14). The template 470 has a right angle arm472 with a locating ball 474 at the end thereof. The arm 472 extends adistance that is substantially the same as the lateral displacement ofthe guide tube 200 from pivot point 205 above the incision point 207 inFIG. 2C (see also the trocar 487 at the incision point 485 in FIG. 2B).The mounting bracket 25 is adjusted on the support post 19 so that theball 474 coincides with the intended incision point of the patient.Thereafter, the template is removed and when the instrument 14 is thenclamped to the mounting bracket, the guide tube 17 will be in the properposition vis-a-vis the patient's incision. Thus, the template 470 isused to essentially position the bracket 25 where it is desired to belocated with the ball 474 coinciding with the incision point. Once thetemplate is removed and the instrument is secured, the guide tube 17will be in the proper position relative to the incision.

[0197] In connection with the operation of the present system, once thepatient is on the table, the drive unit 8 is clamped to the table. It'sposition can be adjusted along the table by means of the attachingmember 212. The lower arm 19A of the rigid support rod 19 is secured tothe table by the bracket 216. The surgeon determines where the incisionis to be made. The mounting bracket on the rigid rod 19 is adjusted andthe template 470 is secured to the clamp 25. The ball 474 on thetemplate is lined up with the incision so as to position the securingrod 19 and clamp 25 in the proper position. At that time the rigid rod19 and the securing clamp 25 are fixed in position. Then the template isremoved and the instrument 14 is positioned on the clamp 25. Theincision has been made and the guide tube 17 is inserted through theincision into the patient and the instrument 14 is secured at the fixedposition of mounting bracket 25.

[0198] With regard to the incision point, reference is made to FIG. 2Bwhich shows the incision point along the dashed line 485. Also shown atthat point is the cannula 487. In some surgical procedures it is commonto use a cannula in combination with a trocar that may be used to piercethe skin at the incision. The guide tube 17 may then be inserted throughthe flexible cannula so that the tool is at the operative site. Thecannula typically has a port at which a gas such as carbon dioxideenters for insufflating the patient, and a switch that can be actuatedto desufflate. The cannula may typically include a valve mechanism forpreventing the escape of the gas.

C2—Slave Cabling and Decoupling (FIGS. 8E-8L)

[0199]FIG. 8E illustrates a mechanical cabling sequence at the slavestation from the drive unit 8, through adaptor 15 and insert 16, to thetool 18. Reference will again be made to FIG. 8E after a description offurther details of the slave station.

[0200] In the present embodiment the cable conduits 21 and 22 aredetachable from the drive unit 8. This is illustrated in FIG. 8F whereinthe drive unit includes separable housing sections 855 and 856. Theinstrument 14 along with the attached cable conduits 21 and 22 andhousing section 856 are, as a unit, of relatively light weight andeasily maneuverable (portable) to enable insertion of the instrument 14into the patient prior to attachment to the bracket 25 on support post19.

[0201]FIG. 8F is an exploded perspective view of the cable drivemechanism and instrument illustrating the de-coupling concepts of thepresent embodiment at the slave station S. A section of the surgicaltabletop T which supports the rigid post 19 is shown. The drive unit 8is supported from the side of the tabletop by an L-shaped brace 210 thatcarries an attaching member 212. The brace 210 is suitably secured tothe table T. The drive unit 8 is secured to the attaching member 212 bymeans of a clamp 214. Similarly, the rigid support rod 19 is secured tothe attaching member 212 by means of another clamping mechanism 216.

[0202] Also in FIG. 8F the instrument 14 is shown detached from (or notyet attached to) support post 19 at bracket 25. The instrument 14 alongwith cables 21 and 22 and lightweight housing section 856 provide arelatively small and lightweight decoupleable slave unit that is readilymanually engageable (insertable) into the patient at the guide tube 17.

[0203] After insertion, the instrument assembly, with attached cables21, 22 and housing 856, is attached to the support post 19 by means ofthe knob 26 engaging a threaded hole in base 452 of adapter 15. At theother end of the support post 19, bracket 216 has a knob 213 that istightened when the support rod 19 is in the desired position. Thesupport rod 19, at its vertical arm 19A, essentially moves up and downthrough the clamp 216. Similarly, the mounting bracket 25 can move alongthe horizontal arm 19B of the support rod to be secured at differentpositions therealong. A further clamp 214 enables the drive unit 8 to bemoved to different positions along the attaching member 212.

[0204]FIG. 8F also shows the coupler 230 which is pivotally coupled frombase piece 234 by means of the pivot pin 232. The coupler 230 is forengaging with and supporting the proximal end of the instrument insert16.

[0205] Reference is now made to FIG. 8G which illustrates the mechanicalcabling sequence at the slave station. The cabling extends from a motor800 (of the drive unit 8), via adaptor 15, and via the instrument insert16 to the tool 18. The adapter 15 and insert 16 are intercoupled bytheir associated interlocking wheels 324 and 334. Cables 606 and 607,which in reality, are a single-looped cable, extend between theinterlocking wheel 334 and the tool 18. These cables 606, 607 are usedfor pivoting the wrist-joint mechanism (at the tool 18), in thedirection of arrow J5 illustrated in FIG. 8G.

[0206]FIG. 8G also illustrates an idler pulley 344 on the insert 16, aswell as a pair of pulleys 317 associated with the wheel 324 on theadapter 15. Cabling 315 extends from interlocking wheel 324 about thepulleys 317, about an idler pulley 318 and through sheathing 319 toconduit turn buckles 892. The cables 323 extending from the turn buckles892 are wrapped about a coupler spindle 860. Associated with the couplerspindle 860 is a coupler disk 862 secured to an output shaft of one ofthe motors 800 of drive unit 8.

[0207] Reference is now made to further cross-sectional viewsillustrated in FIGS. 8H-8L. FIG. 8H is a partially broken awayfront-elevational view as taken along line 8H-8H of FIG. 8F. FIGS. 8Iand 8J are cross-sectional views taken respectively along lines 8I-8Iand 8J-8J of FIG. 8H. FIG. 8K is a cross-sectional side view taken alongline 8K-8K of FIG. 8H. Lastly, FIG. 8L is a cross-sectional view astaken along line 8L-8L of FIG. 8K.

[0208] These cross-sectional views illustrate a series of seven motors800, one for each of an associated mechanical cabling assembly. In, FIG.8K, there is illustrated one of the motors 800 with its output shaft 865extending therefrom. The motor 800 is secured to a housing wall 866(also shown in FIG. 8F). FIG. 8K also shows the angle iron 868 that isused to support the housing section 855 from the bracket 214 (see FIG.8F).

[0209] A coupler disk 862 is illustrated in FIGS. 8J and 8K, secured tothe shaft 865 by a set screw 869. The coupler disk 862 also supports aregistration pin 871 that is adapted to be received in slots 873 of thecoupler spindle 860. FIGS. 8K and 8L illustrate the pin 871 in one ofthe slots 873. The registration pin 871 is biased outwardly from thecoupler disk by means of a coil spring 874.

[0210] The first housing section 855 also carries oppositely disposedthumb screws 875 (see FIG. 8H). These may be threaded through flanges876 as illustrated in FIG. 8J. When loosened, these set screws enablethe second housing section 856 to engage with the first housing section855. For this purpose, there is provided a slot 878 illustrated in FIG.8F. Once the second housing section 856 is engaged with the firsthousing section 855, then the thumb screws 875 may be tightened to holdthe two housing sections together, at the same time facilitatingengagement between the coupler disks 862 and the coupler spindles 860.

[0211] The cross-sectional view of FIG. 8K shows that at the end ofcoupler disk 862 where it is adapted to engage with the coupler spindle860, the coupler disk is tapered as illustrated at 879. This facilitatesengagement between the coupler disk and the coupler spindle.

[0212] As illustrated in FIG. 8F, the two housing sections 855 and 856are separable from each other so that the relatively compact slave unitcan be engaged and disengaged from the motor array, particularly fromthe first housing section 855 that contains the motors 800. The firsthousing section 855, as described previously, contains the motors 800and their corresponding coupler disks 862. In FIG. 8F, the secondhousing section 856 primarily accommodates and supports the couplerspindles 860 and the cabling extending from each of the spindles to thecable bundles 21 and 22 depicted in FIG. 8F.

[0213]FIGS. 8J and 8K illustrate one of the coupler spindles 860supported within a pair of bearings 881. The cable associated with thecoupler spindle is secured to the coupler spindle by means of a cableclamp screw 883. FIGS. 8J and 8K illustrate the cable extending aboutthe coupler spindle, and secured by the cable clamp screw 883. Theparticular cable illustrated in FIGS. 8J about spindle 860 is identifiedas cable D.

[0214] In FIGS. 8H-8K, the cabling is identified by cables A-G. Thisrepresents seven separate cables that are illustrated, for example, inFIG. 8H as extending into the second housing section 856 with a flexibleboot 885 (see the top of FIGS. 8H and 8K) extending thereabout.

[0215] At the top of the second housing section 856 there is provided aconduit stop or retainer 888 that is secured in place at the top of thehousing section in an appropriate manner. The conduit retainer 888 hasthrough slots 890, one for accommodating each of the cables A-G (seeFIG. 81). Refer in particular to FIGS. 8H and 8K illustrating the cablesA-G extending through the retainer 888 in the slots thereof. Each of thecables may also be provided with a turnbuckle 892 that is useful intensioning the cables. Each turnbuckle 892 screws into an accommodatingthreaded passage in the retainer 888, as illustrated in FIG. 8K.

[0216] In FIG. 8H the coupler spindles are all disposed in a lineararray. To properly accommodate the cabling, the spindles are of varyingdiameter, commencing at the top of the second housing section 856 withthe smallest diameter spindle and progressing in slightly largerdiameter spindles down to the bottom of the second housing section 856where there is disposed the largest diameter coupler spindle.

[0217] The detachability of the two housing sections 855 and 856 enablesthe cleaning of certain components which are disposed above the plane ofthe operating table, here referred to as the sterile field. Morespecifically, the detachable housing 856 with attached cables 21 and 22and instrument 14, needs to be sterilized after use, except for theinstrument insert 16 which is an integral disposal unit. Thesterilization of the designated components may include a mechanicalcleaning with brushes or the like in a sink, followed by placement in atray and autoclave in which the components are subjected to superheatedsteam to sterilize the same. In this manner, the adapter 15 is reusable.Also, the engagement between the adapter 15 and insert 16 is such thatthe disposable insert element may have holes, which are relatively hardto clean, whereas the recleanable adapter element has a minimum numberof corresponding projections, which are relatively easier to clean thanthe holes. By disposable, it is meant that the unit, here the insert 16,is intended for a single use as sold in the marketplace. The disposableinsert interfaces with an adapter 15 which is intended to be recleaned(sterilized) between repeated uses. Preferably, the disposable unit,here the insert 16, can be made of relatively lower cost polymers andmaterials which, for example, can be molded by low-cost injectionmolding. In addition, the disposable instrument insert 16 is designed torequire a relatively minimal effort by the operator or other assistantwho is required to attach the insert to the adapter 15. Morespecifically, the operator is not required to rethread any of themultiple mechanical cabling assemblies.

C3—Slave Instrument Assembly (FIGS. 9-16)

[0218] Further details of the detachable and portable slave unit areshown in FIGS. 9-16. For example, FIG. 11 shows the carriage 226 whichextends from the mounting bracket 25 on support post 19. Below carriage226, a base piece 234 is supported from the carriage 226 by arectangular post 228. The post 228 supports the entire instrumentassembly, including the adaptor 15 and the instrument insert 16 onceengaged.

[0219] As indicated previously, a support yoke 220 is supported in afixed position from the mounting bracket 25 via base 452. Cabling 21extends into the support yoke 220. The support yoke 220 may beconsidered as having an upper leg 236 and a lower leg 238 (see FIG. 12).In the opening 239 between these legs 236, 238 there is arranged thepivot piece 222 with its attached base 240. Below the base 240 andsupported by the pivot pin 225 is a circular disc 242 that is stationaryrelative to the yoke legs 236, 238. A bearing 235 in leg 236, a bearing237 in leg 238, and a bearing 233 in disc 242, allow rotation of thesemembers relative to the pivot pin 225.

[0220] Disposed within a recess in the support yoke 220, as illustratedin FIG. 13, is a capstan 244 about which cables 245 and 246 extend andare coupled to opposite sides of the arcuate segment 248 of pivot piece222. The ends of cables 245 and 246 are secured in holes at oppositesides of arcuate segment 248. The cables 245 and 246 operate inconjunction with each other. At their other ends, these cables connectto a motor. Depending upon the direction of rotation of the motor,either cable 245 or cable 246 will be pulled, causing the pivot price232 to rotate in a direction indicated by J1.

[0221] The base 240 of pivot piece 222 also has at one end thereof anend piece 241 into which are partially supported the ends of rails 224(see FIG. 13). The other ends of the rails are supported by an end piece251, which also has cabling 257, 258 for the carriage 226 extendingtherethrough, such as illustrated in FIG. 14. A capstan 253 is supportedfrom a lower surface of the base 240. Another capstan 256 is supportedwithin the support yoke 220. The cables 257 and 258 extend about thecapstan 256, about disc 242 (which may be grooved to receive thecables), to the carriage 226, and from there about another capstan 260disposed within end member 262 (see FIG. 11). End member 262 supportsthe other ends of the rails 224, upon which the carriage 226transitions. The ends of the cables 257 and 258 are securedappropriately within the carriage. FIG. 11 illustrates by the arrow 227the forward and backward motion of the carriage 226, and thus of theattached actuator 15 toward and away from the operative site.

[0222] Now, reference is made to FIG. 15 illustrating a portion of theslave unit with the instrument insert 16 partially removed and rotatedfrom the base piece 234. FIG. 15 shows a portion of the carriagemechanism, including the carriage 226 supported on rails 224. Asindicated previously, below the carriage 226 there is a support post 228that supports the base piece 234. It is at the base piece 234, thatcabling 22 from the drive unit 8 is received.

[0223] Also extending from the base piece 234 is the guide tube 17 ofadapter 15. The guide tube 17 accommodates, through its center axialpassage, the instrument insert 16. Also, supported from the base piece234, at pivot pin 232, is the adaptor coupler 230. The adaptor coupler230 pivots out of the way so that the instrument insert 16 can beinserted into the adaptor 15. FIG. 15 shows the instrument insert 16partially withdrawn from the adaptor 15. The pivot pin 232 may be longerthan the distance between the two parallel bars 270 and 272 carried bybase piece 234, so that the pin not only allows rotation, but can alsoslide relative to bars 270 and 272. This permits the coupler 230 to notonly pivot, but also to move laterally to enable better access of theinstrument insert 16 into the base piece 234. The instrument insert 16has a base (coupler) 300 that in essence is a companion coupler to theadapter coupler 230.

[0224] With further reference to FIG. 15, the instrument insert 16 iscomprised of a coupler 300 at the proximal end, and at the distal end anelongated shaft or stem, which in this embodiment has a more rigidproximal stem section 301 and a flexible distal stem section 302 (seeFIG. 15A). The distal stem section 302 carries the tool 18 at its distalend. The instrument coupler 300 includes one or more wheels 339 whichlaterally engage complimentary wheels 329 of the coupler 230 on adaptor15. The instrument coupler 300 also includes an axial wheel 306 at itsdistal end through which the stem 301 extends, and which also engages awheel on the adaptor, as to be described below in further detail. Theaxial engagement wheel 306 is fixed to the more rigid stem section 301,and is used to rotate the tool 18 axially at the distal end of theflexible stem section 302 (as shown by arrow J4 in FIG. 2B).

[0225] The base piece 234 has secured thereto two parallel spaced-apartbars 270 and 272. It is between these bars 270 and 272 that is disposedthe pivot pin 232. The pivot pin 232 may be supported at either end inbearings in the bars 270 and 272, and as previously mentioned, haslimited sliding capability so as to move the adapter coupler 230 awayfrom base piece 234 to enable insertion of the instrument insert 16. Aleg 275 is secured to the pivot pin 232. The leg 275 extends from thecoupler 230 and provides for pivoting of coupler 230 with respect tobase piece 234. Thus, the combination of pivot pin 232 and the leg 275permits a free rotation of the coupler 230 from a position where it isclear to insert the instrument insert 16 to a position where the coupler230 intercouples with the base 300 of the instrument insert 16. Asdepicted in FIG. 15, the bars 270 and 272 also accommodate therethroughcabling from cable bundles 271.

[0226] The base piece 234 also rotatably supports the rigid tube 17(illustrated by arrow J3 in FIG. 2B). As indicated previously, it is theconnection to the carriage 226 via post 228 that enables the actuator 15to move toward and away from the operative site. The rotation of thetube 17 is carried out by rotation of pulley 277 (see FIG. 15). A pairof cables from the bundle 271 extend about the pulley 277 and can rotatethe pulley in either direction depending upon which cable is activated.To carry out this action, the tube 17 is actually supported on bearingswithin the base piece 234. Also, the proximal end of the tube 17 isfixed to the pulley 277 so that the guide tube 17 rotates with thepulley 277.

[0227] Also supported from the very proximal end of the tube 17, is asecond pulley 279 that is supported for rotation about the actuator tube17. For this purpose a bearing is disposed between the pulley 279 andthe actuator tube. The pulley 279 is operated from another pair ofcables in the bundle 271 that operate in the same manner. The cabling issuch that two cables couple to the pulley 279 for operation of thepulley in opposite directions. Also, as depicted in FIG. 15, the pulley279 has a detent at 280 that is adapted to mate with a tab 281 on theaxial wheel 306 of instrument coupler 300. Thus, as the pulley 279 isrotated, this causes a rotation of the axial wheel 306 and acorresponding rotation of flexible and rigid sections 301, 302 of theinstrument insert 16, including the tool 18.

[0228] Again referring to FIG. 15, a block 310 is secured to one side ofthe coupler 230. The block 310 is next to the leg 275 and contains aseries of small, preferably plastic, pulleys that accommodate cabling315. These cables extend to other pulleys 317 disposed along the lengthof the coupler 230. Refer also to the cabling diagram of FIG. 8E.

[0229] In this embodiment, the coupler 230 includes wheels 320, 322 and324. Each of these wheels is provided with a center pivot 325 to enablerotation of the wheels in the coupler 230. The knob 327 is used tosecure together the adapter coupler 230 and the base coupler 300 of theinstrument insert 16.

[0230] For the three wheels, 320, 322 and 324, there are sixcorresponding pulleys 317, two pulleys being associated with each wheel(see FIGS. 8E and 11B). Similarly, there are six pulleys in the block310. Thus, for cabling bundle 315 there are six separate cable conduitsfor the six separate cables that couple to the wheels 320, 322 and 324.Two cables connect to each wheel for controlling respective oppositedirections of rotation thereof.

[0231] Each of the wheels 320, 322 and 324 have a half-moon portion witha flat side 329. Similarly, the instrument base 300 has companion wheels330, 332 and 334 with complimentary half-moon construction forengagement with the wheels 320, 322 and 324. The wheel 320 controls oneof the jaws of the tool 18 (motion J6 in FIG. 2B). The wheel 324controls the other jaw of the tool 18 (motion J7 in FIG. 2B). The middlewheel 322 controls the wrist pivoting of the tool 18 (motion J5 in FIG.2B). Also refer to FIG. 8E showing cabling for controlling toolmovement.

[0232] The coupler 300 of insert 16 has three wheels 330, 332 and 334,each with a pivot pin 331, and which mate with the corresponding wheels320, 322 and 324, respectively of the adaptor coupler. In FIG. 15 theinstrument base piece 300 is shown rotated from its normal position forproper viewing of the wheels. Normally, it is rotated through 180° sothat the half-moon wheels 330, 332 and 334 engage with the correspondingcoupler wheels 320, 322 and 324. Also illustrated in FIG. 15 arecapstans or idler pulleys 340, 342 and 344 associated, respectively,with wheels 330, 332 and 334.

[0233] As shown in FIG. 15A, each wheel of the instrument coupler 300has two cables 376 that are affixed to the wheel (e.g., wheel 334 inFIG. 8E) and wrapped about opposite sides at its base. The lower cablerides over one of the idler pulleys or capstans (e.g., capstan 34 inFIG. 8E), which routes the cables toward the center of the instrumentstem 301. It is desirable to maintain the cables near the center of theinstrument stem. The closer the cables are to the central axis of thestem, the less disturbance motion on the cables when the insert stem isrotated. The cables may then be routed through fixed-length plastictubes that are affixed to the proximal end of the stem section 301 andthe distal end of the stem section 302. The tubes maintain constantlength pathways for the cables as they move within the instrument stem.

[0234] The instrument coupler 300 is also provided with a registrationslot 350 at its distal end. The slot 350 engages with a registration pin352 supported between the bars 270 and 272 of base piece 234. Thecoupler 300 is also provided with a clamping slot 355 on its proximalend for accommodating the threaded portion of the clamping knob 327 (onadapter coupler 230). The knob 327 affirmatively engages andinterconnects the couplers 230 and 300.

[0235] In operation, once the surgeon has selected a particularinstrument insert 16, it is inserted into the adapter 15. The proximalstem 301, having the distal stem 302 and the tool 18 at the distal end,extend through the adapter guide tube 17. FIG. 8 shows the tool 18extending out of the guide tube 17 when the surgical instrument 16 isfully inserted into the adaptor 15. When it is fully inserted, the tab281 on the axial wheel 306 engages with the mating detent 280 in pulley279. Also, the registration slot 350 engages with the registration pin352. Then the coupler 230 is pivoted over the base 300 of the instrumentinsert 16. As this pivoting occurs, the respective wheels of the coupler230 and the coupler 300 interengage so that drive can occur from thecoupler 230 to the insert 16. The knob 327 is secured down so that thetwo couplers 230 and 300 remain in fixed relative positions.

[0236] Reference is also now made to detailed cross-sectional views ofFIGS. 11A, 11B and 11C. FIG. 11A is a cross sectional view taken alongline 11A-11A of FIG. 11. FIG. 11B is a cross-sectional view taken alongline 11B-11B of FIG. 11A. FIG. 11C is a further cross-sectional viewtaken through FIG. 11A along line 11C-11C.

[0237] The base piece 234 of adapter 15 rotatably supports the guidetube 17, allowing rotation J3 shown in FIG. 2B. As noted in FIG. 11A,there are a pair of bearings 360 disposed at each end within the axialpassage 362 in the base piece 234. The rotation of the guide tube 17 iscarried out by rotation of the first pulley 277. In FIG. 11A there is aset screw 364 that secures the pulley 277 to the guide tube 17. Nylonspacers 366 separate various components, such as the base piece 234 andthe pulley 277, the two pulleys 277 and 279, and base 300 and wheel 306.

[0238] A nylon bearing 368 is also provided between the second pulley279 and the guide tube 17. FIG. 11A also shows the proximal stem section301 of the insert 16 inside of the guide tube 17. A nylon bearing 370 issupported within the front block 372 of the insert 16.

[0239] In FIG. 11A, the second pulley 279 is supported from the proximalend of the tube 17. The bearing 368 is disposed between the pulley 279and the tube 17. The pulley 279 has a detent 280 that is adapted to matewith a tab 281 on the axial wheel 306. Thus, when the pulley 279 isrotated by cabling 271 (see FIG. 11C), this causes a rotation of theaxial wheel 306, and a corresponding rotation (motion J4 in FIG. 2B) ofthe sections 301, 302 of the instrument insert 16, including the tool18. The very proximal end of the section 301 is illustrated in FIG. 11Aas being rotatable relative to the bearing 370.

[0240]FIG. 11A also shows the intercoupling of the instrument andadapter couplers 230 and 300. Here wheel 324 is shown interlocked withwheel 334. FIGS. 11A and 11C also show cabling at 376. This cablingincludes six separate cables that extend through the length of the stem301, 302 of the instrument. The cabling is illustrated connecting aboutan idler pulley 344. The cabling associated with wheel 334 is secured bythe cable clamping screw 378. For further details of the cabling, referto FIG. 8E.

[0241]FIG. 11B is a cross-sectional view taken along 11B-11B of FIG. 11Awhich again shows the cooperating wheels 324 and 334. Also illustratedis a cable clamping set screw 380 that is used to secure the cabling 376to wheel 324. A cable guide rail 382 is attached and forms part of thebase of the adapter coupler 230. The cable guide rail 382 contains sixidler pulleys 317, one of which is illustrated in FIG. 11B. It is notedthat cabling 376 extends about this pulley to the cable idler block 310where conduits 315 are coupled. The cable guide idler block 310 includesa series of six idler pulleys shown in dotted outline in FIG. 11B at386.

[0242]FIG. 11C is a cross-sectional view taken along line 11C-11C ofFIG. 11A, which shows further details at the pulley 279. Alsoillustrated is post 228 supporting the base piece 234 of the instrumentinsert, and cabling 376 extending through the instrument.

[0243]FIGS. 16A and 16B illustrate the construction of one form of atool. FIG. 16A is a perspective view and FIG. 16B is an exploded view.The tool 18 is comprised of four members including a base 600, link 601,upper grip or jaw 602 and lower grip or jaw 603. The base 600 is affixedto the flexible stem section 302 (see FIG. 15A). The flexible stem maybe constructed of a ribbed plastic. This flexible section is used sothat the instrument will readily bend through the curved part of theguide tube 17.

[0244] The link 601 is rotatably connected to the base 600 about axis604. FIG. 16B illustrates a pivot pin 620 at axis 604. The upper andlower jaws 602 and 603 are rotatably connected by pivot pin 624 to thelink 601 about axis 605, where axis 605 is essentially perpendicular toaxis 604.

[0245] Six cables 606-611 actuate the four members 600-603 of the tool.Cable 606 travels through the insert stem (section 302) and through ahole in the base 600, wraps around curved surface 626 on link 601, andthen attaches on link 601 at 630. Tension on cable 606 rotates the link601, and attached upper and lower grips 602 and 603, about axis 604(motion J5 in FIG. 2B). Cable 607 provides the opposing action to cable606, and goes through the same routing pathway, but on the oppositesides of the insert. Cable 607 may also attach to link 601 generally at630.

[0246] Cables 608 and 610 also travel through the stem 301, 302 andthough holes in the base 600. The cables 608 and 610 then pass betweentwo fixed posts 612. These posts constrain the cables to passsubstantially through the axis 604, which defines rotation of the link601. This construction essentially allows free rotation of the link 601with minimal length changes in cables 608-611. In other words, thecables 608-611, which actuate the jaws 602 and 603, are essentiallydecoupled from the motion of link 601. Cables 608 and 610 pass overrounded sections and terminate on jaws 602 and 603, respectively.Tension on cables 608 and 610 rotate jaws 602 and 603 counter-clockwiseabout axis 605. Finally, as shown in FIG. 16B, the cables 609 and 611pass through the same routing pathway as cables 608 and 610, but on theopposite side of the instrument. These cables 609 and 611 provide theclockwise motion to jaws 602 and 603, respectively. At the jaws 602 and603, as depicted in FIG. 16B, the ends of cables 608-611 may be securedat 635, for example by the use of an adhesive such as epoxy glue, or thecables could be crimped to the jaws.

[0247] To review the allowed movements of the various components of theslave unit, the instrument insert 16 slides through the guide tube 17 ofadaptor 15, and laterally engages the adaptor coupler 230. The adaptorcoupler 230 is pivotally mounted to the base piece 234. The base piece234 rotationally mounts the guide tube 17 (motion J3). The base piece234 is affixed to the linear slider or carriage assembly (motion J2).The carriage assembly in turn is pivotally mounted at the pivot 225(motion J1).

[0248] Reference is now made to FIGS. 16C and 16D. FIG. 16C is afragmentary perspective view of an alternate set of jaws, referred to asneedle drivers. FIG. 16D is a side elevation view of the needle drivers.This embodiment employs an over-center camming arrangement so that thejaw is not only closed, but also at a forced closure.

[0249] In FIGS. 16C and 16D, similar reference characters are employedwith respect to the embodiment of FIGS. 16A and 16B. Thus, there isprovided a base 600, a link 601, an upper jaw 650 and a lower jaw 652.The base 600 is affixed to the flexible stem section 302. Cabling608-611 operate the end jaws. Linkages 654 and 656 provide theover-center camming operation.

[0250] The two embodiments of FIGS. 16A-16D employ a fixed wrist pivot.An alternate construction is illustrated in FIGS. 16E-16H in which thereis provided, in place of a wrist pivot, a flexible or bending section.In FIGS. 16E-16H, similar reference characters are used for many of theparts, as they correspond to elements found in FIGS. 16A-16D.

[0251] In the embodiment of FIGS. 16E-16H, the tool 18 is comprised ofan upper grip or jaw 602 and a lower grip or jaw 603, supported from alink 601. Each of the jaws 602, 603, as well as the link 601, may beconstructed of metal, or alternatively, the link 601 may be constructedof a hard plastic. The link 601 is engaged with the distal end of theflexible stem section 302. In this regard reference may also be made toFIG. 15A that shows the ribbed, plastic construction of the flexiblestem section 302. FIG. 16E shows only the very distal end of the stemsection 302, terminating in a bending or flexing section 660. Theflexible stem section 302 is constructed so as to be flexible and thushas a substantial length of a ribbed surface as illustrated in FIG. 15A.Also, at the flexible section 660, flexibility and bending is enhancedby means of diametrically-disposed slots 662 that define therebetweenribs 664. The flexible section 660 also has a longitudinally extendingwall 665, through which cabling extends, particularly for operation ofthe tool jaws. The very distal end of the bending section 660 terminateswith an opening 666 for receiving the end 668 of the link 601. Thecabling 608-611 is preferably at the center of the flex section at wall665 so as to effectively decouple flex or bending motions from toolmotions.

[0252] Regarding the operation of the tool, reference is made to thecables 608, 609, 610, and 611. All of these extend through the flexiblestem section and also through the wall 665 such as illustrated in FIG.16G. The cables extend to the respective jaws 602, 603 for controllingoperation thereof in a manner similar to that described previously inconnection with FIGS. 16A-16D. FIGS. 16E-16H also illustrate the cables606 and 607 which couple through the bending section 660 and terminateat ball ends 606A and 607A, respectively. Again, refer to FIG. 16G thatshows these cables. FIGS. 16F and 16H also show the cables 606, 607 withthe ball ends 606A, 607A, respectively. These ball ends are adapted tourge against the very end of the bendable section in opening 666. Whenthese cables are pulled individually, they can cause a bending of thewrist at the bending or flexing section 660. FIG. 16H illustrates thecable 607 having been pulled in the direction of arrow 670 so as to flexthe section 660 in the manner illustrated in FIG. 16H. Pulling on theother cable 606 causes a bending in the opposite direction.

[0253] By virtue of the slots 662 forming the ribs 664, there isprovided a structure that bends quite readily, essentially bending thewall 665 by compressing at the slots such as in the manner illustratedin FIG. 16H. This construction eliminates the need for a wrist pin orhinge.

[0254] The embodiment illustrated in FIG. 16F has a separate link 601.However, in an alternate embodiment, this link 601 may be fabricatedintegrally with, and as part of, the bending section 660. For thispurpose the link 601 would then be constructed of a relatively hardplastic rather than the metal link as illustrated in FIG. 16F and wouldbe integral with section 660.

[0255] In another embodiment, the bending or flexing section 660 can beconstructed so as to have orthogonal bending by using four cablesseparated at 90° intervals and by providing a center support with ribsand slots about the entire periphery. This embodiment is shown in FIGS.16I-16K. The bending section 613 is at the end of flexible stem section302. The cables 608, 609, 610 and 611 are for actuation of the jaws 602and 603 in the same manner as for earlier embodiments. The link 601couples the bending section 613 to the jaws 602 and 603.

[0256] The bending section has a center support wall 614 supporting ribs618 separated by slots 619. This version enables bending in orthogonaldirections by means of four cables 606, 607, 616 and 617, instead of thesingle degree-of-freedom of FIG. 16E. The operation of cables 606 and607 provides flexing in one degree-of-freedom, while an addeddegree-of-freedom is provided by operation of cables 616 and 617.

[0257] Mention has also been made of various forms of tools that can beused. The tool may comprise a variety of articulated tools such as:jaws, scissors, graspers, needle holders, micro dissectors, stapleappliers, tackers, suction irrigation tools and clip appliers. Inaddition, the tool may comprise a non-articulated instrument such as: acutting blade, probe, irrigator, catheter or suction orifice.

C4—Slave Drive Unit (FIGS. 17-17A)

[0258] Reference is now made to the perspective view of the drive unit8, previously illustrated in FIG. 8. FIG. 17 illustrates the drive unit8 with the cover removed. The drive unit is adjustably positionablealong rail 212 by an angle brace 210 that is attached to the operatingtable. Within the drive unit 8 are seven separate motors 800,corresponding to the seven separate controls at the slave station, andmore particularly, to motions J1-J7 previously described in reference toFIG. 2B.

[0259] The drive unit includes a support plate 805 to which there issecured a holder 808 for receiving and clamping the cabling conduits835. The motors 800 are each supported from the support plate 805. FIG.17 also illustrates the electrical interface at 810, with one or moreelectrical connectors 812.

[0260] Regarding support for the motors 800 there is provided,associated with each motor, a pair of opposed adjusting slots 814 andadjusting screws 815. This permits a certain degree of positionaladjustment of the motors, relative to their associated idler pulleys820. The seven idler pulleys are supported for rotation by means of asupport bar 825. FIG. 17 also shows the cabling coming 830 from each ofthe idler pulleys. With seven motors, and two cables coming off of eachmotor for opposite direction control, there are a total of fourteenseparate cables conduits at the bundle 835. The cables move within theconduits in a known manner. The conduits themselves are fixedlysupported and extend from the holder 808 to the adapter 15. Again,reference may be made to FIG. 8 showing the conduit bundles at 21 and22.

[0261] The seven motors in this embodiment control (1) one jaw of thetool J6, (2) the pivoting of the wrist at the tool J5, (3) the other jawof the tool J7, (4) rotation of the insert J4, (5) rotation of theadaptor J3, (6) linear carriage motion J2 and (7) pivoting of theadaptor J1. Of course, fewer or lesser numbers of motors may be providedin other embodiments and the sequence of the controls may be different.

[0262]FIG. 17A illustrates another aspect of the invention—a feedbacksystem that feeds force information from the slave station back to themaster station where the surgeon is manipulating the input device. Forexample, if the surgeon is moving his arm to the left and this causessome resistance at the slave station, the resistance is detected at theslave station and coupled back to one of the motors at the masterstation to drive the input device, such as the hand assembly illustratedherein, back in the opposite direction. This provides an increasedresistance to the surgeon's movements which occurs substantiallyinstantaneously.

[0263]FIG. 17A illustrates schematically a load cell 840 that is adaptedto sense cable tension. FIG. 17A shows one of the pulleys 842 associatedwith one of the motors 800, and cables 845 and 847 disposed about asensing pulley 850. The sensing pulley 850 is coupled to thepiezoelectric load cell 840. The load cell 840 may be disposed in aWheatstone bridge arrangement.

[0264] Thus, if one of the motors is operating under tension, this issensed by the load cell 840 and an electrical signal is coupled from theslave station, by way of the controller 9, to the master station tocontrol one of the master station motors. When tension is sensed, thisdrives the master station motor in the opposite direction (to thedirection of movement of the surgeon) to indicate to the surgeon that abarrier or some other obstacle has been encountered by the element ofthe slave unit being driven by the surgeon's movements.

[0265] The cabling scheme is important as it permits the motors to belocated in a position remote from the adaptor and insert. Furthermore,it does not require the motor to be supported on any moving arms or thelike. Several prior systems employing motor control have motorssupported on moveable arms. Here the motors are separated from theactive instrument area (and sterile field) and furthermore aremaintained fixed in position. This is illustrated in FIG. 8E by themotor 800. FIG. 8E also illustrates a typical cabling sequence from themotor 800 through to the tool 18. Both ends of cabling 315 are securedto the motor at 842 and the motor is adapted to rotate either clockwiseor counterclockwise, in order to pull the cabling in either onedirection or the other. The pair of cabling operates in unison so thatas one cable is pulled inwardly toward the motor, the other cable pullsoutwardly. As illustrated in FIG. 8E, the cables extend over pulley 820to other pulleys, such as the pair of pulleys 317 and control wheel 324associated with coupler 230. From there, the mechanical drive istransferred to the control wheel 334 of the instrument insert 300, whichis coupled to wheel 334 and to the output cables 606 and 607 which drivewrist rotation of the tool 18, identified in FIG. 8E by the motion J5.

[0266] Another important aspect is the use of inter-mating wheels, suchas the wheels 324 and 334 illustrated in FIG. 8E. This permitsessentially a physical interruption of the mechanical cables, but at thesame time a mechanical drive coupling between the cables. This permitsthe use of an instrument insert 16 that is readily engageable with theadaptor, as well as disengagable from the adaptor 15. This makes theinstrument insert 16 easily replacable and also, due to the simplicityof the instrument insert 16, it can be made disposable. Refer again toFIG. 15A which shows the complete instrument insert and its relativelysimple construction, but which still provides an effective couplingbetween the drive motor and the tool.

C5—Slave Guide Tube (FIGS. 19-19D)

[0267] Reference is now made to FIG. 19, a schematic diagramillustrating different placements of the guide tube 17. FIG. 19Aillustrates left and right guide tubes substantially in the sameposition as illustrated in FIG. 1. For some surgical procedures, it maybe advantageous to orient the tubes so that the curvatures are in thesame direction. FIG. 19B shows the ends of the tubes pointing to theright, while FIG. 19C shows the ends of the tubes pointing to the left.Lastly, in FIG. 19D the ends of the tubes are shown converging but in adownwardly directed position. Regarding the different placements shownin FIG. 19, the adjustable clamp 25, illustrated in FIGS. 8A-8C may beuseful, as this provides some added level of flexibility in supportingthe positioning of the guide tubes on both the left and right side.

C6—Slave Motor Control (FIGS. 20-28)

[0268]FIGS. 20 and 21 are block diagrams of the motor control system ofthe present embodiment. In the system of FIG. 1, there are twoinstruments supported on either side of the operating table. Thus, thereare in actuality two separate drive units 8. One of these is considereda left hand (LH) station and the other is considered a right hand (RH)station. Similarly, at the master station, on either side of the chair,as depicted in FIG. 1, there are left hand and right hand master stationassemblies. Accordingly, there are a total of 28 (7×4) separate actionsthat are either sensed or controlled. This relates to seven separatedegrees-of-motion at both the master and slave, as well as at left handand right stations. In other embodiments there may be only a singlestation, such as either a left hand station or a right hand station.Also, other embodiments may employ fewer or greater numbers ofdegrees-of-motion as identified herein.

[0269] Regarding the master station side, there is at least one positionencoder associated with each of degree-of-motion or degree-of-freedom.Also, as previously described, some of the described motions of theactive joints have a combination of motor and encoder on a common shaft.With regard to the master station, all of the rotations represented byJ1, J2 and J3 (see FIG. 2A) have associated therewith, not only encodersbut also individual motors. At the hand assembly previously described,there are only encoders. However, the block diagram system of FIGS. 20and 21 illustrates a combination with motor and encoder. If a motor isnot used at a master station, then only the encoder signal is coupled tothe system.

[0270]FIGS. 20 and 21 illustrate a multi-axis, high performance motorcontrol system which may support anywhere from 8 to 64 axes,simultaneously, using either eight-bit parallel or pulse width modulated(PWM) signals. The motors themselves may be direct current, directcurrent brushless or stepper motors with a programmable digitalfilter/commutater. Each motor accommodates a standard incrementaloptical encoder.

[0271] The block diagram of FIG. 20 represents the basic components ofthe system. This includes a host computer 700, connected by a digitalbus 702 to an interface board 704. The interface board 704 may be aconventional interface board for coupling signals between the digitalbus and the eight individual module boards 706. The set of module boardsis referred to as the motor control sub unit. Communication cables 708intercouple the interface board 704 to eight separate module boards 706.The host computer 700 may be an Intel microprocessor based personalcomputer (PC) at a control station preferably running a Windows NTprogram communicating with the interface board 704 by way of ahigh-speed PCI bus 702 (5.0 KHz for eight channels to 700 Hz for 64channels).

[0272]FIG. 21 shows one of the module boards 706. Each board 706includes four motion control circuits 710. Each of the blocks 710 may bea Hewlett-Packard motion control integrated circuit. For example, eachof these may be an IC identified as HCTL1100. Also depicted in FIG. 21is a power amplifier sub unit 712. The power amplifier sub unit is basedon National Semiconductor's H-bridge power amplifier integrated circuitsfor providing PWM motor command signals. The power amplifier 712associated with each of the blocks 710 couples to a motor X. Associatedwith motor X is encoder Y. Also note the connection back from eachencoder to the block 710. In FIG. 21, although the connections are notspecifically set forth, it is understood that signals intercouplebetween the block 710 and the interface board 704, as well as via bus702 to the host computer 700.

[0273] The motor control system may be implemented for example, in twoways. In a first method the user utilizes the motor control subunit 706to effect four control modes: positional control, proportional velocitycontrol, trapezoidal profile control and integral velocity control.Using any one of these modes means specifying desired positions orvelocities for each motor, and the necessary control actions arecomputed by the motion control IC 710 of the motor control subunit,thereby greatly reducing the complexity of the control system software.However, in the case where none of the on-board control modes areappropriate for the application, the user may choose a second method inwhich a servo motor control software is implemented at the PC controlstation. Appropriate voltage signal outputs for each motor are computedby the PC control station and sent to the motor control/power amplifierunit (706, 712). Although the computation load is mostly placed on thecontrol station's CPU in this case, there are available high performancecomputers and high speed PCI buses for data transfer which canaccommodate this load.

D. Master—Slave Positioning and Orientation (FIGS. 22-28)

[0274]FIG. 22 provides an overview of control algorithm for the presentembodiment. Its primary function is to move the instrument tool 18 insuch a way that the motions of the instrument tool are precisely mappedto that of the surgeon interface device 3 in three dimensional space,thereby creating the feel of the tool being an extension of thesurgeon's own hands. The control algorithm assumes that both thesurgeon's input interface as well as the instrument system always startat predefined positions and orientations, and once the system isstarted, it repeats a series of steps at every sampling period. Thepredefined positions and orientations, relate to the initial positioningof the master and slave stations.

[0275] First, the joint sensors (box 435), which are optical encoders inthe present embodiment, of the surgeon's interface system are read, andvia forward kinematics (box 410) analysis, the current position (seeline 429) and orientation (see line 427) of the input interface handleare determined. The translational motion of the surgeon's hand motion isscaled (box 425), whereas the orientation is not scaled, resulting in adesired position (see line 432) and orientation (see line 434) for theinstrument tool. The results are then inputted into the inversekinematics algorithms (box 415) for the instrument tool, and finally thenecessary joint angles and insertion length of the instrument system aredetermined. The motor command positions are sent to the instrument motorcontroller (box 420) for commending the corresponding motors topositions such that the desired joint angles and insertion length areachieved.

[0276] With further reference to FIG. 22, it is noted that there is alsoprovided an initial start position for the input device, indicated atbox 440. The output of box 440 couples to a summation device 430. Theoutput of device 430 couples to scale box 425. The initial handle (orhand assembly) position as indicated previously is established by firstpositioning of the handle at the master station so as to establish aninitial master station handle orientation in three dimensional space.This is compared to the current handle position at device 430. This isthen scaled by box 425 to provide the desired tool position on line 432to the instrument inverse kinematics box 415.

[0277] The following is an analysis of the kinematic computations forboth box 410 and box 415 in FIG. 22.

Kinematic Computations

[0278] The present embodiment provides a surgeon with the feel of aninstrument as being an extension of his own hand. The position andorientation of the instrument tool is mapped to that of the surgeoninput interface device, and this mapping process is referred to askinematic computations. The kinematic calculations can be divided intotwo sub-processes: forward kinematic computation of the surgeon userinterface device, and inverse kinematic computation of the instrumenttool.

Forward Kinematic Computation

[0279] Based on the information provided by the joint angle sensors,which are optical encoders of the surgeon interface system, the forwardkinematic computation determines the position and orientation of thehandle in three dimensional space.

1. Position

[0280] The position of the surgeon's wrist in three dimensional space isdetermined by simple geometric calculations. Referring to FIG. 23, thex, y, z directional positions of the wrist with respect to the referencecoordinate are

[0281] X_(p)=(L₃ sin θ₃+L₂ cos θ_(2a)) cos θ_(bp)−L₂

[0282] Y_(p)=−(L₃ cos θ₃+L₂ sin θ_(2a))−L₃

[0283] Z_(p)=(L₃ sin θ₃+L₂ cos θ_(2a)) sin θ_(bp)

[0284] where X_(p), Y_(p), Z_(p) are wrist positions in the x, y, zdirections, respectively.

[0285] These equations for X_(p), Y_(p), and Z_(p) represent respectivemagnitudes as measured from the initial reference coordination location,which is the location in FIG. 23 when θ₃ and θ_(2a) are both zerodegrees. This corresponds to the position wherein arm L2 is at rightangles to arm L3, i.e., arm L2 is essentially horizontal and arm L3 isessentially vertical. That location is identified in FIG. 23 ascoordinate location P′ where X_(p)=Y_(p)=Z_(p)=0. Deviations from thisreference are calculated to determine the current position P.

[0286] The reference coordinates for both the master and the slave areestablished with respect to a base location for each. In FIG. 23 it islocation BM that corresponds structurally to the axis 60A in FIG. 2A. InFIG. 25 it is the location BS that corresponds structurally to the axis225A in FIG. 2B. Because both the master and slave structures havepredefined configurations when they are initialized, the locations ofthe master wrist 60A and the slave pivot 225A are known by the knowndimensions of the respective structures. The predefined configuration ofthe master in the illustrated embodiment, per FIG. 23, relates to knownlengths of arms L2 and L3, corresponding to arm 91 or arm 92, and arm 96respectively. The predefined configuration of the slave is similarlydefined, per FIG. 25, by dimensions of arms L_(s) and L_(b) and byinitializing the slave unit with the guide tube 17 flat in one plane(dimension Y=O) and the arm L_(s) in line with the Z axis.

2. Orientation

[0287] The orientation of the surgeon interface handle in threedimensional space is determined by a series of coordinatetransformations for each joint angle. As shown in FIG. 24, thecoordinate frame at the wrist joint is rotated with respect to thereference coordinate frame by joint movements θ_(bp), θ₂, θ₃ and θ_(ax).Specifically, the wrist joint coordinate frame is rotated (−θ_(bp))about the y axis, (−θ_(2a)) about the z axis and θ_(ax) about the x axiswhere θ_(2a) is θ₂−θ₃. The resulting transformation matrix R_(wh) forthe wrist joint coordinate frame with respect to the referencecoordinate is then $R_{wh} = \left\lbrack \quad \begin{matrix}R_{wh11} & R_{wh12} & R_{wh13} \\R_{wh21} & R_{wh22} & R_{wh23} \\R_{wh31} & R_{wh32} & R_{wh33}\end{matrix}\quad \right\rbrack$

[0288] where R_(wh11)=cos θ_(bp1) cos θ_(2a)

[0289] R_(wh12)=cos θ_(bp1) sin θ_(2a) cos θ_(ax)−sin θ_(bp1) sin θ_(ax)

[0290] R_(wh13)=−cos θ_(bp1) sin θ_(2a) sin θ_(ax)−sin θ_(bp1) cosθ_(ax)

[0291] R_(wh21)=−sin θ_(2a)

[0292] R_(wh22=cos θ) _(2a) cos θ_(ax)

[0293] R_(wh23)−cos θ_(2a) sin θ_(ax)

[0294] R_(wh31)sin θ_(bp1) cos ₇₄ _(2a)

[0295] R_(wh32)=sin θ_(bp1) sin θ_(2a) cos θ_(ax)+cos θ_(bp1) sin θ_(ax)

[0296] R_(wh33)=−sin θ_(bp1) sin θ_(2a) sin θ_(ax)+cos θ_(bp1) cosθ_(ax)

[0297] Similarly, the handle coordinate frame rotates joint angles φ and(−θ_(h)) about the z and y axes with respect to the wrist coordinateframe. The transformation matrix R_(hwh) for handle coordinate framewith respect to the wrist coordinate is then$R_{hwh} = \left\lbrack \quad \begin{matrix}R_{hwh11} & R_{hwh12} & R_{hwh13} \\R_{hwh21} & R_{hwh22} & R_{hwh23} \\R_{hwh31} & R_{hwh32} & R_{hwh33}\end{matrix}\quad \right\rbrack$

[0298] where R_(hwh11)=cos φ cos θ_(h)

[0299] R_(hwh12)=−sin φ

[0300] R_(hwh13)=−cos φ sin θ_(h)

[0301] R_(hwh21)=sin φ cos θ_(h)

[0302] R_(hwh22)=cos φ

[0303] R_(hwh23)=−sin φ sin θ_(h)

[0304] R_(hwh31)=sin θ_(h)

[0305] R_(hwh32)=0

[0306] R_(hwh33)=cos θ_(h)

[0307] Therefore, the transformation matrix R_(h) for handle coordinateframe with respect to the reference coordinate is

[0308] R_(h)=R_(wh) R_(hwh)

Inverse Kinematic Computation

[0309] Once the position and orientation of the surgeon interface handleare computed, the instrument tool is to be moved in such a way that theposition of the tool's wrist joint in three dimensional space X_(w),Y_(w), Z_(w) with respect to the insertion point are proportional to theinterface handle's positions by a scaling factor α

[0310] (X_(w)−X_(w) _(—ref) )=αX_(p)

[0311] (Y_(w)−Y_(w) _(—ref) )=αY_(p)

[0312] (Z_(w)−Z_(w) _(—ref) )=αZ_(p)

[0313] where X_(w) _(—ref) , Y_(w) _(—ref) , Z_(w) _(—ref) are theinitial reference positions of the wrist joint. The orientations couldbe scaled as well, but in the current embodiment, are kept identical tothat of the interface handle.

[0314] When X_(w) _(—ref) ,=Y_(w) _(—ref) ,=Z_(w) _(—ref) =0 theforegoing equations simplify to:

[0315] X_(w)=αX_(p)

[0316] Y_(w)=αY_(p)

[0317] Z_(w)=αZ_(p)

[0318] where (X_(w), Y_(w), Z_(w),), (X_(p), Y_(p), X_(p),) and α arethe desired absolute position of the instrument, current position of theinterface handle and scaling factor, respectively.

1. Position

[0319] The next task is to determine the joint angles ω, Ψ and theinsertion length L_(s) of the instrument, as shown in FIG. 25, necessaryto achieve the desired positions of the tool's wrist joint. Given Y_(w),the angle ω is${\omega = {{{\arcsin \left( \frac{Y_{w}}{L_{bs}} \right)}\omega} = {{\sin^{- 1}\left( {Y_{w}/L_{bs}} \right)}\quad {or}}}},$

[0320] where L_(bs)=L_(b) sin θ_(b).

[0321] Referring to FIG. 26, the sine rule is used to determine theinsertion length L_(s) of the instrument. Given the desired position ofthe tool's wrist joint, the distance from the insertion point to thewrist joint, L_(ws) is simply

L_(w)={square root}{square root over (X_(w) ²+Y_(w) ²+Z_(w) ²)}

[0322] Then by the sine rule, the angle θ_(a) is${{\theta_{a} = {\arcsin \left( {\frac{L_{b}}{L_{w}}\sin \quad \theta_{b}} \right)}},{{{and}\quad L_{s}} = {{{L_{w}\left( \frac{\sin \quad \theta_{c}}{\sin \quad \theta_{b}} \right)}\quad {where}\quad \theta_{c}} = {\theta_{b} - \theta_{a}}}}}\quad$

[0323] Having determined ω and L_(s), the last joint angle Ψ can befound from the projection of the instrument on the x-z plane as shown inFIG. 27.

Ψ=θ_(L′) _(w) −θ_(Δ)

[0324] where $\quad \begin{matrix}{{\theta_{\Delta} = \quad {\arccos \quad \left( \frac{L_{s} + {L_{b}\cos \quad \theta_{b}}}{L_{w}^{\prime}} \right)}},} \\{{\theta_{L_{w}^{\prime}} = \quad {\arcsin \left( \frac{X_{wo}}{L_{w}^{\prime}} \right)}},} \\{L_{w}^{\prime} = \quad \sqrt{X_{w}^{2} + {Z_{w}^{2}}^{\quad}}}\end{matrix}$and  X_(wo)  is  the  x-axis  wrist  position  in  referencecoordinate  frame.  

2. Orientation

[0325] The last step in kinematic computation for controlling theinstrument is determining the appropriate joint angles of the tool suchthat its orientation is identical to that of the surgeon's interfacehandle. In other words, the transformation matrix of the tool must beidentical to the transformation matrix of the interface handle, R_(h).

[0326] The orientation of the tool is determined by pitch (θ_(f)), yaw(θ_(wf)) and roll (θ_(af)) joint angles as well as the joint angles ωand Ψ, as shown in FIG. 28. First, the starting coordinate is rotated(θ_(b) −π/2) about the y-axis to be aligned with the referencecoordinate, represented by the transformation matrix R_(o)$R_{o} = \left\lbrack \quad \begin{matrix}{\sin \quad \theta_{b}} & 0 & \left( {{- \cos}\quad \theta_{b}} \right) \\0 & 1 & 0 \\{\cos \quad \theta_{b}} & 0 & {\sin \quad \theta_{b}}\end{matrix}\quad \right\rbrack$

[0327] The wrist joint coordinate is then rotated about the referencecoordinate by angles (−Ψ) about the y-axis and ω about the z-axis,resulting in the transformation matrix R_(w′f),$\quad {R_{w^{\prime}f} =_{\quad}\left\lbrack \quad \begin{matrix}{\cos \quad {\Psi cos}\quad \omega} & \left( {{- \cos}\quad \Psi \quad \sin \quad \omega} \right) & \left( {{- \sin}\quad \Psi} \right) \\{\sin \quad \omega} & {\cos \quad \omega} & 0 \\{\sin \quad \Psi \quad \cos \quad \omega} & \left( {{- \sin}\quad {\Psi sin}\quad \omega} \right) & {\cos \quad \Psi}\end{matrix}\quad \right\rbrack}$

[0328] followed by rotation of (π/2−θ_(b)) about the y-axis, representedby R_(wfw′f).$R_{{wfw}^{\prime}f} = {\left\lbrack \quad \begin{matrix}{\sin \quad \theta_{b}} & 0 & {\cos \quad \theta_{b}} \\0 & 1 & 0 \\{{- \cos}\quad \theta_{b}} & 0 & {\sin \quad \theta_{b}}\end{matrix}\quad \right\rbrack \quad {which}\quad {is}\quad {equal}\quad {to}\quad {R_{o}^{T}.}}$

[0329] Finally, the tool rolls (−θ_(af)) about the x-axis, yaws θ_(wf)about the z-axis and pitches (−θ_(f)) about the y-axis with respect tothe wrist coordinate, are calculated resulting in transformation matrixR_(fwf) $R_{fwf} = \left\lbrack \quad \begin{matrix}R_{fwf11} & R_{fwf12} & R_{fwf13} \\R_{fwf21} & R_{fwf22} & R_{fwf23} \\R_{fwf31} & R_{fwf32} & R_{fwf33}\end{matrix}\quad \right\rbrack$

[0330] where R_(fwf11)=cos θ_(wf) cos θ_(f)

[0331] R_(fwf12)=−sin θ_(wf)

[0332] R_(fwf13)=−cos θ_(wf) sin θ_(f)

[0333] R_(fwf21)=cos θ_(af) sin θ_(wf) cos θ_(f)+sin θ_(af) sin θ_(f)

[0334] R_(fwf22)=cos θ_(af) cos θ_(wf)

[0335] R_(fwf23)=−cos θ_(af) sin θ_(wf) sin θ_(f)+sin θ_(af) cos θ_(f)

[0336] R_(fwf31)=−sin θ_(af) sin θ_(wf) cos θ_(f)+cos θ_(af) sin θ_(f)

[0337] R_(fwf32)=−sin θ_(af) cos θ_(wf)

[0338] R_(fwf33)=sin θ_(af) sin θ_(wf) sin θ_(f)+cos θ_(af) cos θ_(f)

[0339] Therefore the transformation matrix of the tool R_(f) withrespect to the original coordinate is

[0340] R_(f)=R_(o)R_(wf′)R_(o) ^(T)R_(fwf).

[0341] Since R_(f) is identical to R_(h) of the interface handle,R_(fwf) can be defined by

[0342] R_(fwf)=R_(o)R_(wf′) ^(T)R_(o) ^(T)R_(h)=R_(c)$R_{fwf} = {{R_{o}R_{wf}^{T}R_{o}^{T}R_{h}} = {R_{c} = \left\lbrack \quad \begin{matrix}R_{c11} & R_{c12} & R_{c13} \\R_{c21} & R_{c22} & R_{c23} \\R_{c31} & R_{c32} & R_{c33}\end{matrix}\quad \right\rbrack}}$

[0343] where the matrix R_(c) can be fully computed with known values.Using the computed values of R_(c) and comparing to the elements ofR_(fwf), we can finally determine the necessary joint angles of thetool. $\begin{matrix}{{\theta_{wf} = {\arcsin \left( {- R_{c\quad 12}} \right)}},} \\{\theta_{f} = {{\arccos \left( \frac{R_{c\quad 11}}{\cos \quad \theta_{wf}} \right)} = {\arcsin \left( \frac{- R_{c\quad 13}}{\cos \quad \theta_{wf}} \right)}}} \\{\theta_{af} = {{\arccos \left( \frac{R_{c\quad 22}}{\cos \quad \theta_{wf}} \right)} = {\arcsin \left( \frac{- R_{c\quad 32}}{\cos \quad \theta_{wf}} \right)}}}\end{matrix}$

[0344] The actuators, which are motors in the current embodiment, arethen instructed to move to positions such that the determined jointangles and insertion length are achieved.

[0345] Now reference is made to the following algorithm that is used inassociation with the system of the present invention. First arepresented certain definitions. Variable Definitions: (RH - Right Hand,LH - Left Hand)

s_Ls_RH Linear slider joint for RH slave

s_Xi_RH Lateral motion joint for RH slave (big disk in front of slider)

s_Omega_RH Up/down motion joint for RH slave (rotates curved tube)

s_Axl_RH Axial rotation joint for RH slave (rotates instrument insertalong its axis)

s_f1_RH Finger 1 for RH slave

s_f2_RH Finger 2 for RH slave

s_wrist_RH Wrist joint for RH slave

m_base_RH Base rotation joint for RH master

m_shoulder_RH Shoulder joint for RH master

m_elbow_RH Elbow joint for RH master

m_Axl_RH Axial rotation joint for RH master

m_f1_RH Finger 1 for RH master

m_f2_RH Finger 2 for RH master

m_wrist_RH Wrist joint for RH master

Radian[i] Motor axle angle for joint no. i with i being one of abovejoints

Des_Rad[i] Desired motor axle angle for joint no. i

Des_Vel[i] Desired motor axle angular velocity for joint no. i

Mout_f[i] Motor command output for joint no. i

Thetabp1_m_RH Angle of base rotation joint for RH master

Theta2_m_RH Angle of elbow joint for RH master

Theta3_m_RH Angle of shoulder joint for RH master

Xw_m_RH Position of RH master handle in X-axis

Yw_m_RH Position of RH master handle in Y-axis

Zw_m_RH Position of RH master handle in Z-axis

Xwref_m_RH Reference position of RH master handle in X-axis

Ywref_m_RH Reference position of RH master handle in Y-axis

Zwref_m_RH Reference position of RH master handle in Z-axis

Phi_f_m_RH Angle of wrist joint for RH master

Theta_f1_m_RH Angle of finger 1 for RH master

Theta_f2_m_RH Angle of finger 2 for RH master

ThetaAxl_m_RH Angle of axial rotation joint for RH master

Theta_h_m_RH Angle of mid line of fingers for RH master

Theta_f_m_RH Angle of fingers from the mid line for RH master

Xw_s_RH Position of RH slave in X-axis

Yw_s_RH Position of RH slave in Y-axis

Zw_s_RH Position of RH slave in Z-axis

Xwref_s_RH Reference position of RH slave in X-axis

Ywref_s_RH Reference position of RH slave in Y-axis

Zwref_s_RH Reference position of RH slave in Z-axis

alpha Master-to-slave motion scaling factor

Xw_s_b1_RH Motion boundary 1 of RH slave in X-axis

Xw_s_b2_RH Motion boundary 2 of RH slave in X-axis

Yw_s_b1_RH Motion boundary 1 of RH slave in Y-axis

Yw_s_b2_RH Motion boundary 2 of RH slave in Y-axis

[0346] Note the motion boundaries of the slave are used to define thevirtual boundaries for the master system, and do not directly imposeboundaries on the slave system.

[0347] The following represents the steps through which the algorithmproceeds.

[0348] 1. The system is started, and the position encoders areinitialized to zero. This ASSUMES that the system started in predefinedconfiguration. /* Preset Encoder Position for all axis */ for(i=0; i<32;++i) { SetEncoder[i]=0; } /* Convert encoder count to radian */for(i=0;i<32;i++) { Radian[i] = Enc_to_Rad(Encoder[i]); }

[0349] 2. Bring the system to operating positions, Des_Rad[i], and holdthe positions until the operator hits the keyboard, in which case theprogram proceeds to next step. { for(i=0;i<14;i++) /* compute motoroutfor slave robots*/ { Des_Vel[i]= 0.0; Err_Rad[i] = Des Rad[i] −Radian[i]; Err_Vel[i] = Des Vel[i] − Velocity[i]; kpcmd =Kp[i]*Err_Rad[i]; Mout_f[i] =kpcmd + kdcmd;/* Command output to motor */} for(i=14;i<28;i++) /* compute motorout for master robot */ {Des_Vel[i] = 0.0; Err_Rad[i] = Des_Rad[i] − Radian[i]; Err_Vel[i] =Des_Vel[i] − Velocity[i]; kpcmd = Kp[i]*ErrRad[i]; kdcmd = (Kp[i]*Td[i])*Err_Vel[i]; Mout_f[i] = kpcmd + kdcmd;/* Command output to motor */ } }

[0350] 3. Based on the assumption that the system started at thepredefined configuration, the forward kinematic computations areperformed respectively for the master and the slave systems tofind theinitial positions/orientations of handles/tools.

[0351] /* Compute Initial Positions of Wrist for Right Hand Master */

[0352] Thetabp 1o_m_RH =−Radian[m_base_RH]/PR_-bp1;

[0353] Theta3o_m_RH=−Radian[m_shoulder_RH]/PR_(—)3;

[0354] Thetabp1_m_RH =Thetabp1o_m_RH;

[0355] Theta3_m_RH=Theta3o_m_RH;

[0356] Theta2o_m_RH =Theta3o_m_RH−Radian[m_elbow_RH]/PR_(—)2;

[0357] Theta2_m_RH=Theta2o_m_RH;

[0358] Theta2A_m_RH=(Theta2_m_RH−Theta3_m_RH);

[0359] Theta2A_eff_m_RH=Theta2A_m_RH+Theta_OS_m;

[0360] L_m_RH=(L3_m* sin (Theta3o_m_RH)+L2_eff_m* cos(Theta2A_eff_m_RH));

[0361] Xwo_m_RH=L_m_RH * cos(Thetabp1o_m_RH);

[0362] Ywo_m_RH=−(L3_m+L2_eff m* sin (Theta2A_eff_m_RH));

[0363] Zwo_m_RH=L_m_RH * sin (Thetabp1o_m_RH);

[0364] /* Set these initial positions as the reference positions. */

[0365] Xwref_m_RH=Xwo_m_RH=L2 (FIG. 23)

[0366] Ywref_m_RH=Ywo_m_RH=L3

[0367] Zwref_m_RH=Zwo_m_RH=0

[0368] /* Initial Position of the Wrist for Right Hand Slave based onpredefined configurations */

[0369] Ls_RH=Ls;

[0370] Xwo_s_RH=Lbs=X ref_s_RH

[0371] Ywo_s_RH=0.0=Yref_s_RH

[0372] Zwo_s_RH=—(Ls_RH+Lbc)=Zref_s_RH

[0373] /* Compute Initial Orientations for Right Hand Handle */

[0374] Phi_f_m_RH=Radian[m_wrist_H];

[0375] Theta_f1_m_RH=Radian[m_f1_RH];

[0376] Theta_f2_m_RH=−Radian[m_f2_RH]−Theta_f1_m_RH;

[0377] ThetaAx1_m_RH=Radian[m_Ax1_RH];

[0378] Theta_h_m_RH=(Theta_f1_m_RH−Theta_f2_m_RH)2.0; /* angle ofmidline

[0379] Theta_f_m_RH=(Theta_f1_m_RH+Theta_f2_m_RH)/2.0; /* angle offingers from mid line */

[0380] /* Repeat for Left Hand Handle and Slave Instrument */

[0381] 4. Repeat the procedure of computing initialpositions/orientations of handle and tool of left hand based onpredefined configurations.

[0382] 5. Read starting time

[0383] /* Read starting time: init_time */

[0384] QueryPerformanceCounter(&hirescount);

[0385] dCounter=(double)hirescount.LowPart+(double)hirescount.HighPart *(double)(4294967296);

[0386] QueryPerformanceFrequency(&freq);

[0387] init_time=(double)(dCounter/freq.LowPart);

[0388] prev_time=0.0;

[0389]6. Read encoder values of master/slave system, and current time /*Read encoder counters */ for(i=1; i<9; ++i) { Read_Encoder(i); } /*Convert encoder counts to radian */ for(i=0;i<32;i++) { Radian[i] =Enc_to_Rad(Encoder[i]); } /* Get current time */QueryPerformanceCounter(&hirescount); dCounter =(double)hirescount.LowPart + (double)hirescount.HighPart *(double)(4294967296); time_now = (double)(dCounter/freq.LowPart) −init_time delta_time3 = delta_time2; delta_time2 = delta_time1;delta_time1 = time_now − prev_time; prev_time = time_now;

[0390] 7. Compute current positions/orientations of master handle forRight Hand

[0391] /* Compute master handle's position for right hand */

[0392] Thetabp1_m_RH=−Radian[m_base_RH]/PR_bp1;

[0393] Theta3_m_RH=−Radian[m_shoulder_RH]/PR_(—)3;

[0394] Theta2_m_RH=Theta3_m_RH−Radian[m_elbow_RH]/PR_(—)2;

[0395] Theta2A_m_RH=(Theta2_m_RH−Theta3_m_RH);

[0396] Theta2A_eff_m_RH=Theta2A_m_RH+Theta_OS_m;

[0397] L_m_RH=(L3_m* sin_Theta3_m+L2_eff_m* cos_Theta2A_eff_m);

[0398] Xw_m_RH=L_m_RH* cos_Thetabp1_m;

[0399] Yw_m_RH=−(L3_m* cos_Theta3_m+L2_eff_m* sin_Theta2A_eff_m);

[0400] Zw_m_RH=L_m_RH* sin_Thetabp1_m;

[0401] /* Compute master handle's orientation for right hand */

[0402] Phi_f_m_RH=Radian[m_wrist_RH];

[0403] Theta_f₁_m_RH=Radian[m_f1_RH];

[0404] Theta_f2_m_RH=−Radian[m_f2_RH]−Theta_f1_m_RH;

[0405] ThetaAx1_m_RH=Radian[m_Ax1_RH];

[0406] Theta_h_m_RH=(Theta_f1_m_RH−Theta_f2_m_RH)/2.0; /* angle ofmidline */

[0407] Theta_f_m_RH=(Theta_f1_m_RH+Theta_f2_m_RH)/2.0; /* angle offingers from mid line */

[0408] /* Perform coordinate transformation to handle's coordinate */

[0409] Rwh11=cos_Thetabp1_m* cos_Theta2A_m;

[0410] Rwh12=−sin_Thetabp1_m* sin_ThetaAx1_m+cos_Thetabp1_m*sin_Theta2A_m* cos_ThetaAx1_m;

[0411] Rwh13=−sin_Thetabp1_m* cos_ThetaAx1_m−cos_Thetabp1_m*sin_Theta2A_m* sin_ThetaAx1_m;

[0412] Rwh21=−sin_Theta2A_m;

[0413] Rwh22=cos_Theta2A_m* cos_ThetaAx1_m;

[0414] Rwh23=−cos_Theta2A_m* sin_ThetaAx1_m;

[0415] Rwh31=sin_Thetabp1_m* cos_Theta2A_m;

[0416] Rwh32=cos_Thetabp1_m* sin_ThetaAx1_m+sin_Thetabp1_m*sin_Theta2A_m* cos_ThetaAx1_m;

[0417] Rwh33=cos_Thetabp1_m* cos_ThetaAx1_m−sin_Thetabp1_m*sin_Theta2A_m* sin_ThetaAx1_m;

[0418] Rhr11=cos_Phi_f_m* cos_Theta_h_m;

[0419] Rhr12=−sin_Phi_f_m;

[0420] Rhr13=−cos_Phi_f_m* sin_Theta_h_m;

[0421] Rhr21=sin_Phi_f_m* cos_Theta_h_m;

[0422] Rhr22=cos_Phi_f_m;

[0423] Rhr23=−sin_Phi_f_m* sin_Theta_h_m;

[0424] Rhr31=sin_Theta_h_m;

[0425] Rhr32=0.0;

[0426] Rhr33=cos_Theta_h_m;

[0427] Rh11=Rwh11*Rhr11+Rwh12*Rhr21+Rwh13 *Rhr31;

[0428] Rh12=Rwh11*Rhr12+Rwh12*Rhr22+Rwh13*Rhr32;

[0429] Rh13=Rwh11*Rhr13+Rwh12*Rhr23+Rwh13*Rhr33;

[0430] Rh21=Rwh21*Rhr11+Rwh22*Rhr21+Rwh23*Rhr31;

[0431] Rh22=Rwh21*Rhr12+Rwh22*Rhr22+Rwh23*Rhr32;

[0432] Rh23=Rwh21*Rhr13+Rwh22*Rhr23+Rwh23*Rhr33;

[0433] Rh31=Rwh31*Rhr11+Rwh32*Rhr21+Rwh33*Rhr31;

[0434] Rh32=Rwh31*Rhr12+Rwh32*Rhr22+Rwh33*Rhr32;

[0435] Rh33=Rwh31*Rhr13+Rwh32*Rhr23+Rwh33*Rhr33;

[0436] 8. Desired toolposition is computedfor right hand

[0437] /* Movement of master handle is scaled by alpha for tool position*/

[0438] Xw_s_RH=alpha*(Xw_m_RH−Xwref_m_RH)+Xwref_s_RH;

[0439] Yw_s_RH=alpha*(Yw_m_RH−Ywref_m_RH)+Ywref_s_RH;

[0440] Zw_s_RH=alpha*(Zw_m_RH−Zwref_m_RH)+Zwref_s_RH;

[0441] /* The next step is to perform a coordinate transformation fromthe wrist coordinate (refer to FIG. 25 and coordinate Xwf, Ywf and Zwf)to a coordinate aligned with the tube arm Ls. This is basically a fixed45° transformation (refer in FIG. 25 to θ_(b)) involving the sin and cosof θ_(b) as expressed below. */

[0442] Xwo_s_RH=Xw_s_RH* sin_Theta_b+Zw_s_RH* cos_Theta_b;

[0443] Ywo_s_RH=Yw_s_RH

[0444] Zwo_s_RH=−Xw_s_RH* cos_Theta_b+Zw_s_RH* sin_Theta_b;

[0445] 9. Perform inverse kinematic computation for the right hand toobtain necessary joint angles of the slave system such that toolposition/orientation matches that of master handle.

[0446] Omega_RH=asin (Ywo_s_RH/Lbs);

[0447] Lw=sqrt(pow(Xwo_s_RH,2)+pow(Ywo_s_RH,2)+pow(Zwo_s_RH,2));

[0448] Theta_a=asin(Lb/Lw* sin_Theta_b);

[0449] Theta_c=Theta_b−Theta_a;

[0450] Ls_RH=Lw*(sin(Theta_c)/sin_Theta_b);

[0451] Lwp=sqrt(pow(Lw,2)−pow(Ywo_s_RH,2));

[0452] Theta_Lwp=asin(Xwo_s_RH/Lwp);

[0453] Xi_RH=Theta_Lwp−Theta_delta;

[0454] sin_Omega=sin(Omega_RH);

[0455] cos_Omega=cos(Omega_RH);

[0456] sin_Xi=sin(Xi_RH);

[0457] cos_Xi=cos(Xi_RH);

[0458] Ra11=cos_Xi * cos_Omega * sin_Theta_b+sin_Xi * cos_Theta_b;

[0459] Ra12=sin_Omega * sin_Theta_b;

[0460] Ra13=sin_Xi * cos_Omega * sin_Theta_b−cos_Xi * cos_Theta_b;

[0461] Ra21=−cos_Xi * sin_Omega;

[0462] Ra22=cos_Omega;

[0463] Ra23=−sin Xi * sin_Omega;

[0464] Ra31=cos_Xi * cos_Omega * cos_Theta_b−sin_Xi * sin_Theta_b;

[0465] Ra32=sin_Omega * cos_Theta_b;

[0466] Ra33=sin_Xi * cos_Omega * cos_Theta_b+cos_Xi * sin_Theta_b;

[0467] Rb11=Ra11 * sin_Theta_b−Ra13 * cos_Theta_b;

[0468] Rb12=Ra12;

[0469] Rb13=Ra11 * cos_Theta_b+Ra13 * sin_Theta_b;

[0470] Rb21=Ra21* sin_Theta_b−Ra23 * cos_Theta_b;

[0471] Rb22=Ra22;

[0472] Rb23=Ra21* cos_Theta_b+Ra23 * sin_Theta_b;

[0473] Rb31=Ra31* sin_Theta_b−Ra33 * cos_Theta_b;

[0474] Rb32=Ra32;

[0475] Rb33=Ra31* cos_Theta_b+Ra33 * sin_Theta_b;

[0476] Rc11=Rb11*Rh11+Rb12*Rh21+Rb13*Rh31;

[0477] Rc12=Rb11*Rh12+Rb12*Rh22+Rb13*Rh32;

[0478] Rc13=Rb11*Rh13+Rb12*Rh23+Rb13*Rh33;

[0479] Rc21=Rb21*Rh11+Rb22*Rh21+Rb23*Rh31;

[0480] Rc22=Rb21*Rh12+Rb22*Rh22+Rb23*Rh32;

[0481] Rc23=Rb21*Rh13+Rb22*Rh23+Rb23*Rh33;

[0482] Rc31=Rb31*Rh11+Rb32*Rh21+Rb33*Rh31;

[0483] Rc32=Rb31*Rh12+Rb32*Rh22+Rb33*Rh32;

[0484] Rc33=Rb31*Rh13+Rb32*Rh23+Rb33*Rh33;

[0485] sin_Theta_wf_s=−Rc12;

[0486] Theta_wf_s_RH=asin(sin_Theta_wf_s);

[0487] cos_Theta_wf_s=cos(Theta_wf_s_RH);

[0488] /* Compute Theta_f_s_RH */

[0489] var1=Rc11/cos_Theta_wf_s;

[0490] var2=−Rc13/cos_Theta_wf_s;

[0491] Theta_f_s_RH=asin(var2) or acos(var1) depending or region;

[0492] /* Compute ThetaAx1_s_RH */

[0493] var1=Rc22/cos_Theta_wf_s;

[0494] var2=−Rc32/cos_Theta_wf_s;

[0495] ThetaAx1_s_RH=asin(var2) or acos(var1) depending or region;

[0496] 10. Repeat steps 7-9 for left hand system

[0497] 11. Determine motor axle angles necessary to achievedesiredpositions/orientations of the slave systems, and command themotors to the determinedpositions. Des_Rad[s_Ls_RH] =63.04*(Ls_RH−Ls_init_RH − 0.75*(Xi_RH−Xi_init_RH)); Des_Rad[s_Xi_RH] =−126.08*(Xi_RH−Xi_init_RH); Des_Rad[s_Omega_RH] =−23.64*(Omega_RH−Omega_init_RH); Des_Rad[s_Axi_RH] =−23.64*1.3333*(ThetaAxl_s_RH + Omega_RH− Omega_init_RH);Des_Rad[s_wrist_RH] = 18.9*Theta_wf_s_RH; Des_Rad[s_f1_RH] =18.9*(Theta_f_s_RH + Theta_f_m_RH); Des_Rad[s_f2_RH] =18.9*(−Theta_f_s_RH + Theta_f_m_RH); Des_Rad[s_Ls_LH] =−63.04*(Ls_LH−Ls_init_LH − 0.75*(Xi_LH−Xi_init_LH)), Des_Rad[s_Xi_LH] =126.08*(Xi_LH−Xi_init_LH); Des_Rad[s_Omega_LH] =−23.64*(Omega_LH−Omega_init_LH); Des_Rad[s_Ax1_LH] =−23.64*1.3333*(ThetaAxl_s_LH + Omega_LH− Omega_init_LH);Des_Rad[s_wrist_LH] = 18.9*Theta_wf_s_LH; Des_Rad[s_f1_LH] =−18.9*(−Theta_f_s_LH − Theta_f_m_LH); Des_Rad[s_f2_LH] =−18.9*(Theta_f_s_LH − Theta_f_m_LH); /* Compute motor output for slavesystems */ for(i=0;i<14;i++) { Des_Vel[i] = 0.0; Err_Rad[i] = Des_Rad[i]− Radian[i]; Err_Vel[i] = Des_Vel[i] − Velocity[i]; kpcmd =Kp[i]*Err_Rad[i]; kdcmd = (Kp[i]*Td[i])*Err_Vel[i]; Mout_f[i] = kpcmd +kdcmd; } /* Virtual boundaries for master handles */if(Xwo_s_RH>=Xw_s_b1_RH) { Fx_RH = 3.0*k_master*(Xwo_s_RH−Xw_s_b1_RH);Mout_f[m_base_RH] = Fx_RH*cos(0.7854−(Radian[m_base_RH]/14.8));Mout_f[m_shoulder_RH] = Fx_RH*sin(0.7854− (Radian[m_base_RH]/14.8))−1.0*Radian[m_shoulder RH]; } else if (Xwo_s_RH<=Xw_sb2_RH) { Fx_RH =k_master*(Xwo_s_RH−Xw_s_b2_RH); Mout_f[m_base_RH] =Fx_RH*cos(0.7854−(Radian[m_base_RH]/14.8)); Mout_f[m_shoulder_RH] =Fx_RH*sin(0.7854− (Radian[m_base_RH]/14.8))− 1.0*Radian[m_shoulder_RH];} else { Mout_f[m_base_RH]=0.0;Mout_f[m_shoulder_RH]=−1.0*Radian[m_shoulder_RH]; }if(Ywo_s_RH>=Yw_s_b2_RH) { Mout_f[m_elbow_RH] =−k_master*(Ywo_s_RH−Yw_s_b2_RH); } else if (Ywo_s_RH<=Yw_s_b1_RH) {Mout_f[m_elbow_RH] =−k_master*(Ywo_s_RH−Yw_s_b1_RH); } elseMout_f[m_elbow_RH]=0.0; /* Repeat for left master handle */

[0498] 12. Go back to step 6 and repeat.

[0499] Previously there has been described an algorithm for providingcontrolled operation between the master and slave units. The followingdescription relates this operation to the system of FIGS. 1-2.

[0500] The controller 9 receives input signals from the input device 3that represent the relative positions of the different portions of theinput device. These relative positions are then used to drive theinstrument 14 to a corresponding set of relative positions. For example,the input device includes a base 50 (FIG. 2A) to which a first link 90is rotatably connected. A second link 96 is rotatably connected to thefirst link at an elbow joint 94. Connected to the second link 96opposite the elbow joint 94 is a wrist joint 98A and two fingers. Asurgeon may attach a thumb and forefinger to the two fingers and movethe input device to drive the instrument 14.

[0501] As the surgeon operates the input device, rotational position ofthe base (Thetabp1_m_RH), the rotational position of the first linkrelative to the base (Theta3_m_RH), the rotational position of thesecond link relative to the first link (Theta2_m_RH), the angle of thewrist joint relative to the second link (PHI_f_m_RH, i.e., the angle thewrist joint is rotated about an axis perpendicular to the length of thesecond link), the rotary angle of the wrist joint relative to the secondlink (ThetaAx1_m_RH, i.e., the angle the wrist joint is rotate about anaxis parallel to the length of the second link), and the angles of thefingers (Theta_f1_m_RH and Theta_f2_m_RH) are provided to thecontroller.

[0502] When the surgical instrument is first started, the controllerinitializes all of the position encoders in the instrument 14 and theinput device 3, assuming that the system has been started in a desiredinitial configuration. See Sections 1-3 of the algorithm. The initialposition of the input device, e.g., Xwo_m_RH, Ywo_m_RH, and Zwo_m_RH, isthen used to establish a reference position for the input device,Xwref_m_RH, Ywref_m_RH, and Zwref_m_RH. See Section 3 of the algorithm.Initial positions are also established for the instrument 14 based onthe dimensions of the instrument 14. See Section 3 of the algorithm.

[0503] With reference to Section 3 of the algorithm, it is noted thatthere is an assignment of the initial position of the wrist for theslave, and that this is not a forward kinematics calculation based uponjoint angles, but rather is a number based upon the predefinedconfiguration of the slave unit. The coordinate of the slave relates tofixed physical dimensions of the instrument and instrument holder.

[0504] As the surgeon moves the input device 3, the encoder values forthe input device are read and used to compute the current absoluteposition of the input device, i.e., Xw_m_RH Yw_m_RH and Zw_m_RH. SeeSections 6 and 7 of the algorithm. The controller then determines thedesired position of the tool 18 (Xw_s_RH, Yw_s_RH, and Zw_s_RH) based onthe current position of the input device (Xw_m_RH Yw_m_RH, and Zw_m_RH),the reference position for the input device (Xwref_m_RH, Ywref_m_RH, andZwref_m_RH) and the reference position for the instrument 14(Xwref_s_RH, Ywref_s_RH, and Zwref_s_RH). See Section 8 of thealgorithm. The desired position of the tool 18 (Xw_s_RH, Yw_s_RH, andZw_s_RH) is then transformed by a 45° coordinate transformation givingthe desired position (Xwo_s_RH, Ywo_s_RH, Zwo_s_RH) which is used todetermine joint angles and drive motor angles for the instrument 14orientation to match that of the input device. See Sections 8-11 of thealgorithm. Thus, movement of the surgical instrument 14 is determinedbased on the current absolute position of the input device, as well asthe initial positions of the input device and the instrument at the timeof system start-up.

E. Select Features of Described Embodiment

[0505] The control in accordance with the present embodiment, asexemplified by the foregoing description and algorithm, provides animprovement in structure and operation while operating in a relativelysimple manner. For example, the control employs a technique whereby theabsolute position of the surgeon input device is translated into controlsignals to move the instrument to a corresponding absolute position.This technique is possible at least in part because of the particularconstruction of the instrument and controllable instrument holder, whichessentially replace the cumbersome prior art multi-arm structuresincluding one or more passive joints. Here there is initialized an allactive joint construction, including primarily only a single instrumentholder having a well-defined configuration with respect to the insertedinstrument.

[0506] Some prior-art systems rely upon passive joints to initiallyposition the distal tip of the surgical instrument. Because thepositions of the passive joints are initially unknown, the position ofthe distal tip of the surgical instrument with respect to the robot(instrument holder) is also unknown. Therefore, these systems require aninitial calculation procedure. This involves the reading of joint anglesand the computation of the forward kinematics of all elementsconstituting the slave. This step is necessary because the jointpositions of the slave are essentially unknown at the beginning of theprocedure.

[0507] On the other hand, in accordance with the present invention it isnot necessary to read an initial position of joint angles in order todetermine an initial position of the distal tip of the surgicalinstrument. The system of the present invention, which preferablyemploys no passive joints, has the initial position of the distal tip ofthe surgical instrument known with respect to the base of theinstrument. The instrument is constructed with known dimensions, such asbetween base pivot 225 and the wrist (303 at axis 306 in FIG. 2D) of thetool 18. Further, the instrument is initially inserted by the surgeon ina known configuration, such as illustrated in FIGS. 9 and 10, where thedimensions and orientations of the instrument insert and adaptor guidetube are known with respect to the base (pivot 225). Therefore, aninitial position of the surgical instrument distal tip need not becalculated before the system is used.

[0508] The system of the present embodiment is fixed to the end of astatic mount (bracket 25 on post 19) which is manually maneuvered overthe patient, such as illustrated in FIG. 1. Since the initial positionof the surgical instrument tip (tool 18) with respect to the base (pivot225) of the articulate mechanism is invariant, the joint positions areneither read nor is the forward kinematics computed during the initialsetup. Thus, the initial position of the surgical instrument tip isneither computed nor calculated. In addition, because the base of thesystem in accordance with the present embodiment is not necessarilyfixed directly to the surgical table, but rather movable during asurgical procedure, the initial position of the surgical instrument in aworld coordinate system is not knowable.

[0509] Another advantage of the present system is that the instrumentdoes not use the incision in the patient to define a pivot point of theinstrument. Rather, the pivot point of the instrument is defined by thekinematics of the mechanism, independent of the patient incision, thepatient himself, or the procedure. Actually, the pivot point in thepresent system is defined even before the instrument enters the patient,because it is a pivot point of the instrument itself. This arrangementlimits trauma to the patient in an area around the incision.

[0510] From an illustrative standpoint, the base of the instrument maybe considered as pivot 225 (FIG. 8), and the wrist may be the pivotlocation 604 (axis) depicted in FIG. 16B (or axis 306 in FIG. 2D). Theguide tube 17 has known dimensions and because there are no other joints(active or passive) between the pivot 225 and wrist joint, all of theintervening dimensions are known. Also, the instrument when placed inposition has a predefined configuration such as that illustrated inFIGS. 1, 9 and 10 with the guide tube flat is one plane.

[0511] The guide tube 17 may also have an alignment mark therealongessentially in line with the pivot 225, as shown in FIG. 9. This marksthe location where the guide tube 17 is at the patient incision point.The result is minimal trauma to the patient occasioned by any pivotingaction about pivot 225.

[0512] Another advantage is the decoupling nature of the present system.This decoupling enables the slave unit to be readily portable. Here theinstrument, drive unit and controller are decouplable. A sterilizedadaptor 15 is inserted into a patient, then coupled to a non-steriledrive unit 8 (outside the sterile field). Instrument inserts 16 are thenremovably attached to the surgical adaptor to perform the surgicalprocedure. The system of the present embodiment separates the drive unit8 from the instruments 16. In this way, the instruments can bemaintained as sterile, but the drive unit need not be sterilized.Furthermore, at the time of insertion, the adaptor 15 is preferablydecoupled from the drive unit 8 so it can be readily manually maneuveredto achieve the proper position of the instrument relative to the patientand the patient's incision.

[0513] In accordance with the present embodiment, the instrument inserts16 are not connected to the controller 9 by way of any input/output portconfiguration. Rather, the present system employs an exclusivelymechanical arrangement that is effected remotely and includes mechanicalcables and flexible conduits coupling to a remote motor drive unit 8.This provides the advantage that the instrument is purely mechanical anddoes not need to be contained within a sterile barrier. The instrumentmay be autoclaved, gas sterilized or disposed in total or in part.

[0514] The present system also provides an instrument that is far lesscomplex than prior art robotic system. The instrument is far smallerthan that of a typical prior art robotic system, because the actuators(motors) are not housed in the articulate structure in the presentsystem. Because the actuators are remote, they may be placed under theoperating table or in another convenient location and out of the sterilefield. Because the drive unit is fixed and stationary, the motors may beof arbitrary size and configuration, without effecting the articulatedmechanics. Finally, the design allows multiple, specialized instrumentsto be coupled to the remote motors. This allows one to design aninstrument for particular surgical disciplines including, but notlimited to, such disciplines as cardiac, spinal, thoracic, abdominal,and arthroscopic.

[0515] A further important aspect is the ability to make the instrumentdisposable. The disposable element is preferably the instrument insert16 such as illustrated in FIG. 15A. This disposable unit may beconsidered as comprising a disposable, mechanically drivable mechanismsuch as the coupler 300 interconnected to a disposable tool 18 through adisposable elongated tube such as the stem section 301, 302 of theinstrument insert. This disposable implement is mounted so that themechanically drivable mechanism may be connectable to and drivable froma drive mechanism. In the illustrated embodiment the drive mechanism mayinclude the coupler 230 and the associated drive motors. The disposableelongate tube 301, 302 is inserted into an incision or orifice of apatient along a selected length of the disposable elongated tube.

[0516] The aforementioned disposable implement is purely mechanical andcan be constructed relatively inexpensively, thus lending itself readilyto being disposable. Another factor that lends itself to disposabilityis the simplicity of the instrument distal end tool (and wrist)construction. Prior tool constructions, whether graspers or other types,are relatively complex in that they usually have multiple pulleys at thewrist location for operation of different degrees-of-freedom there,making the structure quite intricate and relatively expensive tomanufacture. On the other hand, in accordance with the presentinvention, no pulleys are required and the mechanism in the location ofthe wrist and tool is simple in construction and can be manufactured atfar less expense, thus readily lending itself to disposability. One ofthe aspects of the invention that has enabled elimination of thepulleys, or the like, is the decoupling of tool action relative to wristaction by passing the tool actuation cables essentially through thecenter axis (604 in FIGS. 16A and 16B) of the wrist joint. Thisconstruction allows proper wrist action without any significant actionbeing conveyed to the tool cables, and furthermore allows for a verysimple and inexpensive construction at the distal end of the implement.

[0517] Another aspect is the relative simplicity of the system, both inits construction and use. This provides an instrument system that is farless complex than prior robotic systems. Furthermore, by enabling adecoupling of the slave unit at the motor array, there is provided areadily portable and readily manually insertable slave unit that can behandled quite effectively by the surgeon or assistant when the slaveunit is to be engaged through a patient incision or orifice. Thisenables the slave unit to be positioned through the incision or orificeso as to dispose the distal end at a target or operative site. A supportis then preferably provided so as to hold a base of the slave unit fixedin position relative to the patient at least during a procedure that isto be carried out. This initial positioning of the slave unit with apredefined configuration immediately establishes an initial referenceposition for the instrument from which control occurs via a controllerand user interface.

[0518] This portable nature of the slave unit comes about by virtue ofproviding a relatively simple surgical instrument insert in combinationwith an adaptor for the insert that is of relatively smallconfiguration, particularly compared with prior large articulatedrobotic arm(s) structures. Because the slave unit is purely mechanical,and is decouplable from the drive unit, the slave unit can be readilypositioned by the operator. Once in position, the unit is then securedto the support and the mechanical cables are coupled with the driveunit. This makes the slave unit both portable and easy to position inplace for use.

[0519] Another advantage of the system is the ability to position theholder or adaptor for the instrument with its distal end at theoperative site and maintained at the operative site even duringinstrument exchange. By way of example, and with reference to FIG. 2B,the instrument holder is represented by the guide tube 17 extending tothe operative site OS. When instruments are to be exchanged, the distalend of the guide tube 17 essentially remains in place and theappropriate instruments are simply inserted and/or withdrawn dependingon the particular procedure that is being carried out.

[0520] Accordingly, one of the advantages is the ease of exchanginginstruments. In a particular operation procedure, there may be amultitude of instrument exchanges and the present system is readilyadapted for quick and easy instrument exchange. Because the holder oradaptor is maintained in position, the surgeon does not have to be ascareful each and every time that he reintroduces an instrument into thepatient. In previous systems, the instrument is only supported through acannula at the area of the incision and when an instrument exchange isto occur, these systems require removal of the entire assembly. Thismeans that each time a new instrument is introduced, great care isrequired to reposition the distal end of the instrument so as to avoidinternal tissue or organ damage. On the other hand, in accordance withthe present invention, because the holder or adaptor is maintained inposition at the operative site, even during instrument exchange, thesurgeon does not have to be as careful as the insert simply slidesthrough the rigid tube adaptor. This also essentially eliminates anychance of tissue or organ damage during this instrument exchange.

[0521] Having now described a limited number of embodiments of thepresent invention, it should be apparent to those skilled in the artthat numerous other embodiments and modifications thereof arecontemplated as falling within the scope of the present invention.

1. A method of controlling a surgical instrument that is inserted in apatient for facilitating a surgical procedure and controlled remotelyfrom an input device manipulated by a surgeon at a user interface, saidmethod comprising the steps of: initializing the position of thesurgical instrument without calculating its original position, and theposition of the input device under electronic control; said initializingincluding establishing an initial reference position for the inputdevice and an initial reference position for the surgical instrumentcalculating the current absolute position of the input device as it ismanipulated by the surgeon; determining the desired position of thesurgical instrument based upon; the current position of the inputdevice, the reference position of the input device, and the referenceposition of the surgical instrument, and moving the surgical instrumentto the desired position so that the position of the surgical instrumentcorresponds to that of the input device.
 2. A method as set forth inclaim 1 wherein the input device has position sensors, and the step ofinitializing includes initializing these position sensors.
 3. A methodas set forth in claim 2 wherein the initializing is to zero.
 4. A methodas set forth in claim 1 including computing an initial referenceorientation for the input device.
 5. A method as set forth in claim 4including computing a desired orientation for the surgical instrument.6. A method as set forth in claim 5 including computing a desiredposition for the surgical instrument.
 7. A method as set forth in claim1 wherein said initializing step includes performing a forward kinematiccomputation from the input device.
 8. A method as set forth in claim 2including reading position sensor values and current time.
 9. A methodas set forth in claim 8 wherein the calculating step includescalculating both the position and orientation of the input device.
 10. Amethod as set forth in claim 1 including calculating the currentorientation of the input device.
 11. A method as set forth in claim 1wherein said step of determining includes performing an inversekinematic computation.
 12. A method as set forth in claim 1 wherein saiddetermining step includes a transformation into an earth coordinatesystem.
 13. A method as set forth in claim 12 wherein from saidtransformation there are determined joint angles and drive motor anglesfor the surgical instrument orientation.
 14. A method of controlling atool of a surgical instrument that is inserted in a patient for carryingout a surgical procedure and is controlled remotely by way of acontroller from an input device at a user interface, said methodcomprising the steps of: setting the input device at an initialreference configuration and under controller control; setting thesurgical instrument in the patient at an initial predefined referenceconfiguration without controller control; calculating the currentabsolute position of the input device; determining the desired locationof the tool by a kinematic computation that accounts for at least theinitial reference configuration of the input device and the currentabsolute position of the input device; and moving the surgicalinstrument to the desired position so that the location of the toolcorresponds to that of the input device.
 15. A method as set forth inclaim 14 wherein said step of determining is also based upon the initialreference configuration of the tool.
 16. A method as set forth in claim14 wherein the input device has position sensors, and the step ofsetting includes initializing these position sensors.
 17. A method asset forth in claim 14 including computing an initial referenceorientation for the input device.
 18. A method as set forth in claim 14including computing a desired orientation for the surgical instrument.19. A method as set forth in claim 14 wherein said calculating stepincludes performing a forward kinematic computation from the inputdevice.
 20. A method as set forth in claim 14 including calculating thecurrent orientation of the input device.
 21. A method as set forth inclaim 14 wherein said step of determining includes performing an inversekinematic computation.
 22. A method as set forth in claim 14 whereinsaid determining step includes a transformation into an earth coordinatesystem.
 23. A method as set forth in claim 22 wherein from saidtransformation there are determined joint angles and drive motor anglesfor the surgical instrument orientation.
 24. A system for controlling aninstrument that is inserted in a patient to enable a surgical procedureand controlled remotely from an input device controlled by a surgeon ata user interface, said system comprising: a base; a first link rotatablyconnected to said base; an elbow joint for rotatably connecting thesecond link to the first link; a handle; a wrist member connecting thehandle to the distal end of the second link; and a controller coupled toat least said base and links and for receiving signals representativeof; a rotational position of the base, a rotational position of thefirst link relative to the base, and a rotational position of the secondlink relative to the first link.
 25. A system as set forth in claim24wherein said controller also receives signals representative of theangle of the wrist member relative to the second link and the rotaryangle of the wrist member relative to the second link.
 26. A system asset forth in claim 25 wherein said controller also receives signalsrepresentative of the angles associated with fingers of the tool.
 27. Asystem as set forth in claim 24 wherein said wrist member comprises awrist joint.
 28. A system as set forth in claim 24 including at leastone position sensor associated respectively with the base, first linkand second link.
 29. A system as set forth in claim 28 wherein signalsfrom the position sensors couple to the controller.
 30. A system as setforth in claim 29 wherein an initial reference position of the base andlinks is established prior to manipulation by the surgeon.
 31. A controlsystem for an instrument that is controlled remotely from an inputdevice, said system comprising: a forward kinematics block for computingthe position of the input device; an initialization block for storing aninitial reference position of said input device; an inverse kinematicsblock coupled from said forward kinematics block and said initializationblock for receiving information from said forward kinetics block of thecurrent input device position; and a controller block coupled from saidinverse kinematics block for controlling the position of the instrumentin response to manipulations at the input device.
 32. A control systemas set forth in claim 31 including a scaling block coupled between saidforward kinematics block and said inverse kinematics block for scalingmotions imparted at the input device.
 33. A control system as set forthin claim 32 including an output from said forward kinematics blockdirectly to said inverse kinematics block representative of currentinput device orientation.
 34. A control system as set forth in claim 33including a combining device coupled from said forward kinematics blockand said initialization block to said scaling block for providing asignal to said inverse kinematics block representative of desiredinstrument position.
 35. A control system as set forth in claim 31wherein said input device includes a wrist and a handle.
 36. A controlsystem as set forth in claim 35 wherein the position of the wrist isexpressed in x, y and z coordinates.
 37. A control system as set forthin claim 36 wherein the orientation of the handle is determined by aseries of coordinate transformations.
 38. A control system as set forthin claim 37 wherein a transformation matrix is provided for the handlecoordinate frame with respect to a reference coordinate frame.
 39. Acontrol system as set forth in claim 37 including a transformationmatrix R_(wh) for the wrist joint coordinate with respect to a referencecoordinate, and a transformation matrix R_(hwh) for the handlecoordinate with respect to the wrist coordinate.
 40. A control system asset forth in claim 39 wherein a transformation matrix R_(h) for thehandle coordinate with respect to the reference coordinate is:R_(h)=R_(wh)R_(hwh).
 41. A method of controlling a medical implementremotely from an input device that is controlled by an operator, saidmethod comprising the steps of: positioning the medical implement at aninitial start position at an operative site for the purpose offacilitating a medical procedure; establishing a fixed positionreference coordinate representative of the initial start position ofsaid medical implement based upon a base point of the implement and anactive point of the implement being in a known relative dimensionalconfiguration, positioning the input device at an initial startposition; establishing a fixed position reference coordinaterepresentative of the initial start position of said input device;calculating the current position of the input device as it iscontrolled; determining the desired position of the medical implementbased upon; the current position of the input device, the fixed positionreference coordinate of the input device, and the fixed positionreference coordinate of the medical implement, and moving the medicalimplement to the desired position so that the position of the medicalimplement corresponds to that of the input device.
 42. A method as setforth in claim 41 wherein, in said step of positioning the medicalimplement, the medical implement comprises a surgical instrument.
 43. Amethod as set forth in claim 42 wherein, in said step of positioning themedical implement, the medical implement comprises a catheter.
 44. Amethod as set forth in claim 41 wherein said step of positioning themedical implement includes physically placing the distal end of themedical implement at the operative site.
 45. A method as set forth inclaim 44 wherein said medical implement is placed withoutpre-computation of a coordinate position at which it is placed.
 46. Amethod as set forth in claim 45 wherein said step of positioning themedical implement is only controlled by manual placement without anyelectric pre-computation of a predetermined coordinate position tocontrol the actual placement of the medical implement
 47. A method asset forth in claim 41 wherein, in said step of positioning the medicalimplement, the medical implement comprises a surgical instrument havinga tool and a wrist, said established reference coordinate correspondingto an initial position of a location on said wrist.
 48. A method as setforth in claim 41 further including providing an electronic controllerfor controlling said medical implement and wherein the step ofpositioning the medical implement includes manually placing the medicalimplement without computation by said controller of an initialcoordinate position.
 49. A method as set forth in claim 41 furtherincluding providing an electronic controller for controlling saidmedical implement and wherein the step of positioning the input deviceincludes initially moving the input device under controller control soas to establish the reference coordinate position of the input device.50. A method as set forth in claim 42 including storing in thecontroller the reference coordinate position of the input device.
 51. Amethod as set forth in claim 41 wherein said step of establishingincludes performing a forward kinematic computation.
 52. A method as setforth in claim 51 wherein said calculating step includes calculatingboth the position and the orientation of the input device.
 53. A methodas set forth in claim 52 wherein said step of determining includesperforming an inverse kinematic computation.
 54. A method of controllinga surgical instrument remotely from an input device and by way of anelectronic controller, said method comprising the steps of: insertingthe surgical instrument through an incision in the patient so as todispose the distal end of the instrument at an initial start position;establishing a fixed position reference coordinate system correspondingto a fixed known position on the surgical instrument at the initialstart position of said surgical instrument; positioning the input deviceat an initial start position; establishing a fixed position referencecoordinate system representative of the initial start position of saidinput device; calculating the current absolute position of the inputdevice as it is controlled; determining the desired position of thesurgical instrument based upon the current absolute position of theinput device, and the fixed position reference coordinate system for therespective surgical instrument and input device; and moving the surgicalinstrument to the desired position so that the position of the surgicalinstrument corresponds to that of the input device.
 55. A method as setforth in claim 54 wherein said step of positioning the input deviceincludes initializing the location of the input device under control ofthe controller.
 56. A method as set forth in claim 55 wherein saidsurgical instrument is initially positioned without control from saidcontroller.
 57. A method as set forth in claim 54 wherein the initialstart position is determined only by manual insertion.
 58. A method asset forth in claim 57 wherein the step of positioning the input devicecomprises initially moving the input device under controller control soas to establish the reference coordinate position of the input device.59. A method as set forth in claim 58 including storing in thecontroller the reference coordinate position of the input device.
 60. Amethod as set forth in claim 54 wherein said step of calculatingincludes performing a forward kinematic computation.
 61. A method as setforth in claim 60 wherein said calculating step includes calculatingboth the position and the orientation of the input device.
 62. A methodas set forth in claim 61 wherein said step of determining includesperforming an inverse kinematic computation.
 63. A method of controllinga medical implement remotely from an input device and by way of anelectronic controller, said method comprising the steps of: insertingthe medical implement through an incision in a patient so as to disposethe medical implement in a pre-selected initial configuration; assigninga fixed initial reference coordinate to a work element of the medicalimplement based upon a known dimension between said work element and abase of the medical implement; positioning the input device at aninitial start position; establishing a fixed initial referencecoordinate representative of the initial start position of the inputdevice; calculating the current position of the input device as it iscontrolled; determining the desired position of the medical implementbased upon at least the current position of the input device; and movingthe medical implement so that the position thereof corresponds to thatof the input device.
 64. A method as set forth in claim 63 wherein saidstep of inserting the medical implement includes inserting a surgicalinstrument.
 65. A method as set forth in claim 63 wherein said step ofinserting the medical implement includes inserting a catheter.
 66. Amethod as set forth in claim 63 wherein said step of inserting themedical implement includes inserting a distal end of the medicalimplement through the incision so as to be disposed at a target site.67. A method as set forth in claim 63 wherein said step of inserting themedical implement includes placing the medical implement withoutpre-computation of a coordinate position at which it is placed.
 68. Amethod as set forth in claim 63 wherein said step of assigning includesplacing the medical implement without pre-computation to determine acoordinate position
 69. A method as set forth in claim 63 wherein saidstep of establishing a fixed initial reference coordinate for the inputdevice includes executing a forward kinematic computation to determinethe reference coordinate.
 70. A method as set forth in claim 69 whereinsaid step of executing a forward kinematic computation includesdetermining both the position and orientation of the input device.
 71. Amethod as set forth in claim 69 wherein said step of executing a forwardkinematic computation includes determining a position by a geometriccalculation.
 72. A method as set forth in claim 71 including determiningan orientation by a transformation matrix.
 73. A method as set forth inclaim 63 wherein said step of determining includes performing an inversekinematic computation.
 74. A method as set forth in claim 73 includingdetermining joint angles and insertion length of the instrument.
 75. Amethod as set forth in claim 74 including determining the instrumentorientation.
 76. A method as set forth in claim 63 wherein said step ofdetermining includes a coordinate transform.
 77. A processor and amemory device containing a program of instructions for the processorwhich include; receiving an insertion length of a medical instrumentinserted in a patient; and determining a distal end location of theinstrument at a target site in the patient from the insertion length.78. The processor and device of claim 77 wherein the instrument has astraight proximal portion and curved distal portion.
 79. The processorand device of claim 78 wherein the instrument lies in a single plane.80. The processor and device of claim 79 wherein the instrument is arigid guide member.
 81. The processor and device of claim 77 wherein theinstrument is inserted and then fixed at a pivot axis outside thepatient.
 82. The processor and device of claim 81 wherein the pivot axisis generally aligned with an insertion point at which the instrument isinserted into the patient.
 83. The processor and device of claim 82wherein the program of instructions includes determining a subsequentlocation of the distal end associated with pivoting about the pivotaxis.
 84. The processor and device of claim 82 wherein the program ofinstructions includes determining a subsequent location of the distalend associated with axial rotation of the instrument.
 85. The processorand device of claim 82 wherein the program of instructions includesdetermining a subsequent location of the distal end associated withlinear translation along a length axis of the instrument.
 86. Theprocessor and device of claim 81 wherein the program of instructionsincludes determining a subsequent movement of the distal end in a singleplane about the pivot axis.
 87. The processor and device of claim 81wherein the pivotal axis is a reference point used by the program ofinstructions in determining subsequent movement of the distal end. 88.The processor and device of claim 77 wherein the program of instructionsdetermines subsequent movement of the distal end in a robotic system.89. The processor and device of claim 88 wherein a master stationcontrols movement of the distal end at a slave station.
 90. Theprocessor and device of claim 88 wherein the processor is disposedbetween a user input and a drive unit for driving the instrument. 91.The processor and device of claim 77 wherein the program of instructionsdetermines a position and orientation of the instrument.
 92. Theprocessor and device of claim 77 wherein the instrument is a guidemember.
 93. A processor and a memory device containing a program ofinstructions for the processor which include; receiving a coordinaterepresentative of the desired location of the distal end of a medicalinstrument at a target site in a patient; and determining from saidcoordinate an insertion length for the medical instrument so as tolocate the distal end at the target site.